Toad Tower is a frightening castle located far beyond in the mountains of Wartwood Swamp, where the fiercest toads reside. It originally served as home to the cruel warlord Captain Grime.
Toad Tower was described as a rather scary dark castle and according to Sprig Plantar, the toads that live there are the bravest, fiercest warriors and served as the home of Captain Grime and temporary home of Sasha who was originally a prisoner there until she became second-in-command.
Toad Tower doesn't actually appear in this episode, but it could be seen on a map showing all of Wartwood Swamp.
It makes a brief cameo near the end while Captain Grime is talking with Sasha.
One-Eyed Wally later blows it up by using a dozen boomshrooms which causes most of Toad Tower to fall apart therefore, forcing Grime and his army to leave.