Lake Roccaluce/Series

Original
Sixteen years before Season 1, after sending her younger sister Bloom to Earth for her safety, Daphne proceeds to defend her kingdom against the Ancestral Witches. But, despite her best efforts, she was eventually overpowered and parishes. As a result, her spirit resides Lake Roccaluce.

Retcon
Sixteen years before Season 1, when the Ancestral Witches were about to attack Domino, Daphne acquired the Sirenix power to fight them.

When the Ancestresses attacked Domino, Daphne tried using her Sirenix powers to fight the Witches but her powers turned against her because of the Witches' curse and turned her into a bodiless spirit, and she became bound to the cave where the Source of Sirenix is found.

Season 1
In Season 1, the Lake made some appearances as the home of Daphne's spirit, from where she attempted to communicate with Bloom.

After the Trix steal Bloom's Dragon Flame, Bloom goes to Domino where Daphne tells her that she was once the nymph of Lake Roccaluce. Later, after a failed attempt to retrieve the Dragon Flame from the Trix by sneaking into Cloud Tower, Bloom and Sky wander across the forests and, upon hearing Daphne's calling, Bloom goes to Lake Roccaluce where Bloom regains control of her powers after Daphne reveals to her that she still has the Dragon Flame in her.

Season 3
In Season 3, Valtor uses the Spell of the Elements to flood Cloud Tower with Lake Roccaluce's waters and he used the caves from under the then dried lake as a trap for Bloom. When Bloom used her Fairy Dust to free all the spells he had stolen, Valtor called the Spell of the Elements, and involuntarily the water of Lake Roccaluce as well, back to him, seemingly drowning him, though he survived.

Season 5
The Lake appeared in Season 5 also in "Back to Alfea", when Bloom asked Daphne the location of the Sirenix Book.

Tritannus later entered Lake Roccaluce after stealing the powers of Nissa, the Selkie who guards the Ocean Gate of Magix, and he captured Daphne in the hopes of knowing the secret of how to acquire Sirenix from her.

After the Trix attack Marion and Oritel, Daphne reveals to Tritannus that her Sirenix powers are protected by the Source of Sirenix found in Lake Roccaluce. Tritannus then goes to Daphne's cave in Lake Roccaluce and destroys the Source of Sirenix, causing the Lake to start drying up, and he then stole Daphne's Sirenix powers from her and gives them to the Trix. The Winx, after defeating a pollution monster created by Tritannus, combine their powers with those of the Selkies to restore the Source, which causes their Guardians of Sirenix to call upon Omnia, the Supreme Guardian of Sirenix, who gives Sirenix powers to the Winx, as they had completed their Sirenix Quest. From there, the Winx enter the Infinite Ocean.

Season 6
The Lake appeared in "Inspiration of Sirenix", when the Winx searched for the Inspiration of Sirenix. The Trix later entered Lake Roccaluce and battle Winx, but were defeated.

The Secret of the Lost Kingdom
Lake Roccaluce appeared in Bloom's dream where Bloom and Daphne talked about Domino, hoping Oritel and Marion were still alive.