Lake Roccaluce

Lake Roccaluce, also called the Lake of the Fortress of Light or Light Rock Lake, is a lake introduced in Season 1.

Overview
Lake Roccaluce is a lake which is located right in the middle of the Magic Dimension in front of Alfea, Cloud Tower, and Red Fountain, not far from Magix City. The nymphs of Magix are said to live in its depths.

The Lake is partly surrounded by the Black Mud Swamp and the Fortress of Light is found above it.

Daphne's Cave
Daphne, Bloom's sister, once lived there and the cave became her residence after she was turned into a bodiless spirit when the Ancestral Witches destroyed her home planet of Domino.

The source of Lake Roccaluce's waters is found in the cave, and it is also the Source of Sirenix, where Omnia, the Supreme Guardian of Sirenix, resides.

Water Nymphs' Village
The Undines live in the lake, near the Black Mud Swamp. They live in a village of air bubbles attached to water lilies. These bubbles are made of a special material that they make out of a plant called Xilith.

Revenge of the Trix
After the incident at the library, Faragonda decides to take Bloom on an astral journey to show what she knows about Daphne. At Lake Roccaluce, Faragonda takes Bloom to where Daphne resides, a underwater cave where a bright, blinding light is emitting from. She encourages Bloom to enter and Daphne appears before her holding a decorated box. When it opens, it reveals a crown. Bloom is not sure what to make of it and is confused but before she could get more information, the astral journey stops.

The Battle for Magix
Daphne calls Bloom to her as she and Sky are walking in the forest back to Alfea during the Trix's rampage. There, Bloom enters the lake on her own and Daphne appears before her to give encouragement, reasoning and most of all, how to regain her powers as she had never lost them. Thanks to Daphne, Bloom was able to reach deep inside herself and regain her powers.

Trivia

 * "Lake Roccaluce" translates to "Lake Light Fortress".
 * In the 4Kids dub, it is named "Lake Ephemera" and "Lake Chrysalis".