From Bulbapedia, the community-driven Pokémon encyclopedia.
Izabe Lake (Japanese: イザベ池 Izabe Lake) is an anime-exclusive location near the Valley of Destruction on Izabe Island in the Hoenn region.
The lake is the current resting place of an ancient stone Poké Ball containing a giant Claydol said to have caused "The Great Destruction" on Izabe Island over a thousand years ago. The destruction occurred over seven days and seven nights until Claydol was sealed in a stone Ball by a legendary white sage. Sigourney, the island's current sage, continues to watch over Lake Izabe and the stone Poké Ball to avoid the same havoc reoccurring.
In Claydol Big and Tall, Team Rocket broke the original stone Poké Ball in an attempt to steal the valuable Pokémon inside. However, the giant Claydol proved too powerful and went on a rampage towards a nearby village. Following Sigourney's ancient book, a beautiful maiden was required to distract Claydol. While Jessie, Meowth and May all tried, Wobbuffet, disguised in a maid's outfit and playing the flute, attracted Claydol's attention. Meanwhile, everyone levered a second stone Poké Ball and managed to seal the Claydol inside once again. The Ball rolled into Lake Izabe after Team Rocket tried to again steal Claydol.
Pokémon seen near Izabe Lake