It is probably safe to say that there is no actual fountain on earth which literally possesses the power to cause any man who sets foot in it to emerge from the waters half-man and half-woman.
And yet Ovid, in the fourth book of his Metamorphoses, relates the story of the son of Hermes and Aphrodite whose fateful encounter with the nymph Salmacis imparted this power to the waters of the spring, as though the location and effects of that place were actually well-known in his day.
Ovid actually tells the story as a "story-within-a-story" in his poem, during an extended episode in which the daughters of Minyas refuse to set aside their work and join in the rituals of the god Dionysus, but instead continue weaving -- and as they do so, they relate stories of various interactions with the divine realm, debating amongst themselves as they do so whether or not the gods could really perform all the wonders described (a question which is answered at the end of the tale, when the impious daughters who failed to recognize the divinity of Dionysus are transformed into chattering bats).
The final story they tell before this fate befalls them is the story of Samacis and Hermaphroditus. Alcithoe, one of the daughters of Minyas, begins:
I will explain the way in which the fountain
of Salmacis, whose enervating waters
effeminate the limbs of any man
who bathes in it, came by its reputation,
for though the fountain's ill effects are famous,
their cause has never been revealed before. Metamorphoses 4. 396 - 401.
Thus in the excellent translation of Charles Martin published in 2005 and available here and elsewhere where books are sold; many earlier translations are available on the web.
I find that very literal translations can be the most helpful for examining Star Myths for the celestial clues that may have been included in the original but which may have been "lost in translation" if the translator does not pick them up and bring them across into the new language. With literal translations, the clues are usually carried over, because the translator is trying to render the words of the original as closely as possible into the new language, even if the result sounds a little unusual.
Here is a link to such a version, from the nineteenth century scholar Roscoe Mongan. The account of the encounter between Salmacis and Hermaphroditus at the pool which ever after bore its unique powers (and ever after was named after the nymph herself, becoming "the fountain is translated there as follows (Alcithoe is speaking as she and her sisters weave at their loom):
Learn, then, from what cause Salmacis became notorious, and why, with its enfeebling waters, it unnerves the limbs bathed in it. The cause lies hid, but the power of the spring is very well known. The Naiads nursed, in the caves of Ida, a boy, born to Mercury from the Cythereian goddess, whose face was of that kind in which both father and mother might be recognised; he also obtained his name from them. As soon as he had completed thrice five years, he forsook his native mountains and, leaving Ida, that had been his nurse, he loved to wander about in unknown places, and to see unknown rivers, his curiosity lessening the fatigue. He proceeds to the Lycian cities also, and to the Carians that border upon Lycia. He sees here a pool of water, clear even to the very ground below. There are not here any fenny reeds, nor barren sedges, nor rushes with sharp points. The water is transparent, yet the borders of the pool are fringed with fresh turf, and with plants perpetually blooming. A nymph dwells there, but one who is not suited either for the chase, nor one who is won't to bend the bow, nor one who is to compete in the foot-race, and she alone, of all the naiads, was not known to the swift Diana. The report is, that her sisters often said to her: "Salmacis, do take either a javelin, or a painted quiver, and combine they leisure time with the toilsome chase." She does not take either a javelin or a painted quiver, and she does not combine her hours, spent in leisure, with the toilsome chase; but at one time she bathes her beautiful limbs in her own fountain; often she smooths down her tresses with a comb of Cytorian box-wood; and consults the waters which she looks into [to see] what is most becoming to herself [i.e., she looks into the pool to see which way of arranging her hair is the most beautiful on her]. And, at another time, having her person enveloped in a transparent garment, she reclines either upon the soft leaves, or upon the soft grass. She often gathered flowers, and now, also, by chance, she was gathering them when she saw the youth, and wished to possess him as soon as she beheld him. However, although she was hastening to approach him, she did not actually approach to him until she had arranged herself, and until she had looked at her raiment, and had assumed her [most captivating] aspect, and deserved to appear beautiful.
Then thus she began to speak: "O boy most worthy to be believed to be a god! if thou art a god, thou mayst be Cupid; or, if thou art a mortal, happy are they who gave thee birth. [. . .] If thou hast any spouse, let my pleasure be secretly enjoyed; or, if thou hast none, let me be [thy consort], and let us enter the same bridal chamber." After these words the naiad became silent. A blush suffused the features of the young. He knows not what love is, but even the very act of blushing was becoming to him. Such a colour is in apples hanging upon a tree exposed to the sun, or in painted ivory, or in the moon blushing beneath her brightness, when he auxiliary brazen cymbals resound in vain.
To the nymph soliciting, without cessation, at least such kisses as he might give to a sixte, and to her now advancing her arms to his neck, as white as ivory, he says: "Wilt thou cease? or must I fly and leave these places, along with thyself also?" Salmacis was alarmed, and said: "I surrender these places free to thee, O stranger!" and, with a retreating step, she pretends to depart. But then, also looking back and being concealed in a thicket of shrubs, she lay hid, and placed on the ground her bended knees. But he, as being only a boy, and as if being unobserved, goes hither and thither on the lonely sward, and dips in the playful ripples [first] the soles of his feet, and [afterwards] his feet as far as the ankles. Nor is there any delay; being delighted with the temperature of the gentle waters, he throws off from his tender person his soft garments. But then, indeed, Salmacis was amazed, and became excited with desire for his unrobed beauty; the eyes, too, of the nymph burn, no otherwise than the sun, when shining most brilliantly with a clear disk, it is reflected from the opposite image of a mirror. With difficulty can she endure delay; and now with difficulty can she defer her joy. Now she desires to embrace him; and now, distracted with love, she can scarcely restrain herself. He, striking his body with his hands bent inwards, swiftly plunges into the stream, and throwing out his arms alternately, shines in the clear waters, just as if any one were to enclose ivory figures, or white lilies, within clear glass.
"We have conquered!" exclaims the naiad, "lo, he is mine!" and, throwing all her garments far away, she plunges into the midst of the waters, and seizes him, resisting her, and snatches kisses in the struggle, and puts down her hand and touches his breast much against his will; and clings around the youth, sometimes in one direction, sometimes in another. Finally she entangles him struggling hard against her, and anxious to escape from her, like a serpent, which the royal bird takes up and carries away aloft it, as it hangs suspended, holds fast his head and feet and entangles his expanded wings with its tail.
And [she clung to him as closely] as the tendrils of the ivy are wont to entwine themselves around the tall trunks of trees, and as the polypus, but letting down his sucker on all sides, grasps his enemy captured beneath the water. The descendant of Atlas persists, and denies to the nymph her hoped-for joy. She presses him closely, and as she was clinging to him with her entire person she said: "Although thou mayest struggle, O thou obstinate being! notwithstanding this thou shalt not escape. May ye so ordain it, O ye gods! and let no length of time separate him from me or me from him!" These supplications obtained the favour of the [lit. their own] deities, for the persons of these two, becoming incorporated, are united together, and one form includes both of them, just as if anyone should see from beneath a bark formed over both of them, branches to become united in their growth and to spring up equally. Thus, after their bodies were united in a firm embrace, they are no longer two bodies; but yet the form of them is two-fold; so that it could be called neither woman nor boy; it seems to be neither, and yet both.
Wherefore, when Hermaphroditus sees that the clear waters, into which he had descended as a man, had rendered him only half a male, and that his limbs were becoming softened in them; holding up his hands, he says, but now not with the voice of a man: "O both father and mother! grant this favour to your son who has the name of you both. Whosoever comes as a man to these streams, let him go out thence as half a man, and let him suddenly become effeminate in the waters that he touches." Both parents being moved, confirmed the words of their double-shaped son, and tinged the fountain with a drug that renders sex ambiguous. 11 - 14.
Where is this famous fountain, whose properties were apparently well-known? Is it possible that it actually existed in ancient times, or that its waters still possess such properties to this day?
I believe in fact that this fountain actually does exist -- but that it is located in the celestial realms, and not on earth. The pool is found at the widest, brightest section of the Milky Way band, where the two zodiac constellations of Scorpio and Sagittarius are stationed on either side (visible this time of year in the hours prior to sunrise).
The clearest indication that this is the section of the night sky to which this myth is giving reference is the extended metaphor in which the poet compares the clinging of Salmacis to the person of Hermaphroditus to a serpent being carried upwards by an eagle, and twisting and wrapping about the bird. This metaphor clearly points to the two Milky Way constellations of Aquila and Scorpio, the Eagle of Aquila being located above the Scorpion in this brightest portion of the Milky Way band.
In fact, I believe that from the clues in the ancient poem itself (the best extant version of this particular myth, although it is also referenced by the earlier historian Diodorus Siculus, and obviously has an origin much earlier in the mythology of ancient Greece rather than Rome, since the boy's name is a combination of the Greek names of the god Hermes and goddess Aphrodite, rather than the Roman versions of the same, although Ovid of course uses their Roman names Mercury and Venus), the youth who dips his feet into the waters is played by the constellation Ophiucus, which is flanked by serpents on either side -- just as Salmacis is described as clinging to him with her entire body, like a serpent, first on one side and then on the other.
In the diagram below, you can see that Ophiucus is "dipping his feet" into the pool (the widest and brightest part of the Milky Way band):
The nymph Salmacis is probably Scorpio, crouching in a thicket before she rushes out to wrap herself around Hermaphroditus, although earlier in the poem some of the description suggests Virgo (particularly the part about gathering flowers when she first spies Hermaphroditus -- can you see what celestial features might play a role in this part of the account?)
The struggle that ensues contains an extended metaphor involving an eagle ("the royal bird") and a snake -- again, this probably refers to Aquila and Scorpio, and is a pattern found in many myths and traditions involving this part of the sky.
After Hermaphroditus emerges from the pool, now merged with Salmacis and sharing the gender of both man and woman, the waters from then on have the power of effecting the same change upon those with whom they come in contact.
The constellation Sagittarius, which in ancient Greek myth frequently plays characters of either male or female sex (as you will see if you examine the evidence discussed in my latest book, Star Myths of the World and how to interpret them, Volume Two) may play the role of Hermaphroditus emerging from the stream, now changed.
Thus, the "action" of the myth can be said to commence on the right of our screen as we look at the star chart above (the west) and proceed towards the east -- a very significant direction of movement, from a spiritual point of view (this is also discussed in the latest book). The two figures of Hermaphroditus and Salmacis begin on the right side of the sky (as we look towards the south in the northern-hemisphere view above), then they go into the fountain and there is a struggle (described in terms of a serpent entwining about an eagle) and emerge on the other side as one hermaphroditic figure (Sagittarius).
From the above analysis, we can be confident that the above encounter never actually took place on this earth between literal, historical figures who merged into one being.
But that does not mean that the myth itself is "not true."
In fact, I believe the myths are actually true, and on many profound levels (perhaps not just "many levels" but rather infinite levels, descending deeper and deeper without end).
One of the ways that they are true is that they describe the experience of our human soul, "plunged down" into this material realm, a realm characterized by the "lower elements" of earth and water (as opposed to the "upper elements" of air and fire).
When our invisible spirit takes on a material body, we become for a time a "blended being" composed of both divine soul and physical form.
Myths having to do with the "plunge" into the waters of incarnation often do involve the constellation Virgo, who stands at the edge of the "lower half" of the year, at the point of autumnal equinox (see discussion in this previous post).
But the plunge down into matter often involves (at first) the loss of awareness of our spiritual or divine inner spark, as we sink more and more into sensual enjoyment of the body (and Salmacis is described as basically spending all of her time in such enjoyment, looking at her reflection in the water, combing her hair and bathing her limbs, and lying around in the grass wearing diaphanous garments). At a certain point, there is a "spiritual turn" at which we begin to have an awakening of awareness of our spiritual nature -- and I believe that this myth actually depicts that very point of awakening, when Salmacis sees the child of Hermes and Aphrodite and exclaims that he must be of divine origin, and that she must have him.
The integration of the two natures is actually the point of this famous incident, I believe -- portrayed here in the frank sexual imagery sometimes employed in ancient myth, but actually using the sexes as a way of expressing spiritual concepts in allegorical or metaphorical form: to "clothe" the truths of the invisible reality in the physical forms of nature, to better convey them to our deeper understanding.
As we begin to understand how to interpret the myths in the language which they are actually speaking, the language in which they actually ask us to listen to them, we can begin to hear a message that we might otherwise have totally missed.
Each and every ancient myth is worthy of deep and careful contemplation, and the above explication of the myth of Salmacis and Hermaphroditus may serve as an example of the sort of examination and meditation we can profit by applying to the myths of the portions of the corpus of ancient wisdom which draws each of us most strongly (some will perhaps find themselves drawn to the myths of ancient Greece, others to the myths of ancient India or ancient Japan, or of the cultures spread across the vast Pacific, or the continents of Africa or Australia or the Americas, and so forth).
In fact, the above discussion only barely ripples the surface (so to speak) of the deep pool of the fountain of Salmacis: one could meditate upon this tiny portion of the stories in Ovid's work, and in the wider context of the daughters of Minyas, for years on end and probably never exhaust the amazing lessons that it might hold for him or her.