After acquiring the Monrepo estate in 1788, the park was adorned with a large number of sculptures depicting ancient gods. However, due to vandalism by visitors, their number gradually decreased, and by the mid-19th century, only three park sculptures remained: "Neptune" in the "Temple" pavilion, "Väinämöinen" in the St. Nicholas Gorge, and the marble "Narcissus."

The sculpture of Narcissus was purchased by Baron Nikolai from the Italian architect Vincenzo Brenna along with other damaged statues. The depiction of the ancient Greek deity was missing its right arm. V. Brenna promised to send a craftsman to repair the purchased sculptures but did not keep his promise. Nikolai decided to decorate the open pool of the "Silmiya Spring" with the statue of Narcissus gazing at his reflection. It is believed that in his poem "The Monrepo Estate in Finland. 1804," the estate owner romanticized the Finnish name of the spring "Silmä" (Finnish for "eye": local legend held that the water from the spring had healing powers that improved eyesight). According to Nikolai, who himself suffered from eye diseases, the beautiful nymph Silmiya took pity on the shepherd who loved her and restored his sight.

By order of the estate owner, Monferran designed the pavilion over the "Silmiya Spring" in the 1820s: featuring an iron grille, a niche for the statue of Narcissus, and a lion's mask from which a stream of water flowed. Since then, the spring became known as "Narcissus." The water from the spring was remarkably pure and was even sold in pharmacies.

"The guide told us that the spring's water is famous for its healing power, taste, and freshness. Indeed, I have never drunk such water in my life." This is perhaps the most famous mention of the spring. It was left in the memoirs of Anna Kern, who visited Monrepo in 1829. "It is cold, clear as mountain crystal, and contains much vitality. There is a magnificent rose bush by the spring," she wrote many years after visiting the park.

Anna Kern's guide and companions—the composer Mikhail Glinka, the writer Orest Somov, and Pushkin's close friend, the poet Anton Delvig—were accompanied by the daughter of Signor Motti, the owner of the Vyborg hotel where Anna Kern and her friends stayed. Signorita Motti told the truth: the local residents indeed revered the spring's water as possessing healing powers—an ancient legend endowed it with the ability to cure eye diseases.

It is assumed that the spring's original name was "Silmä" ("silmä," Finnish for "eye"). This explains why, when creating Monrepo, Ludwig Nikolai named the spring "Silmiya Spring." Later, the name "Narcissus" appeared...

It is possible that the legend about the origin of the underground spring, told by Ludwig Heinrich Nikolai in the poem "The Monrepo Estate in Finland. 1804," is a poetic retelling and reinterpretation of an old folk legend.
Here is what the poet Nikolai told us:

"Once upon a time, a beautiful nymph named Silmiya lived in these places. One day, a shepherd named Lars saw her and fell in love. But Silmiya did not notice his love. Doomed to suffer, Lars shed bitter tears, longing from unrequited love. No one knew the cause of the poor shepherd's misfortune. He confided his secret only to his closest friend. Lars's emotional suffering was so great, and he cried so many tears that eventually he was struck blind. Then his friend, entrusted with his heartfelt affairs, found Silmiya and told her about it.

When the nymph Silmiya learned that she was the cause of all Lars's troubles, she appealed to the Sun to heal the poor shepherd. (Recall that in Greek mythology, nymphs are bearers of ancient wisdom, secrets of life and death, and they heal and cure). At that very moment, a miraculous spring burst forth from the rock, flowing eastward. According to ancient Finnish beliefs, water from such a spring can restore sight. Lars washed in the healing water, and... the white light appeared to him again in all its diversity. Lars sought Silmiya to thank her for saving him. But he did not find her... and could not find her... ("Oh, Sun," Silmiya said, "let the eyes that loved me see your light again!.." And at that moment, she turned into a spring...) Every day, Lars came to the spring with a modest offering in gratitude for his healing... And it seemed to Lars that in its murmur he heard Silmiya's voice..."

This tradition has been preserved. To this day, it is customary to throw coins into the small granite pool, where a bronze lion gazes sadly, as an offering to the nymph Silmiya. It is believed that only after this does the spring acquire its healing power, and then one may wash with its water, which flows from underground into the second pool surrounding the first.

The name "Narcissus" was indeed given to the spring later. Most likely, this happened when Paul Nikolai became the owner of Monrepo. As for the pavilion decorating the spring, it was designed by Auguste Montferrand in the 1820s.

Like many other monuments in Vyborg, the pavilion over the "Narcissus" spring suffered greatly during the Soviet-Finnish wars (1939–1944). The sculpture of Narcissus was lost. During restoration work carried out in 1974, the grille (though made not of cast iron but steel with cast aluminum elements) and the lion's mask were restored. Over time, due to ground layer shifts, water began to flow not from the mask but from the bottom of the pool.

Sources:

https://www.parkmonrepos.org/portfolio/79

https://ru.wikipedia.org/wiki/Нарцисс_(источник)