The Camelot is a medieval castle according to the British legends of King Arthur.
Camelot in mentioned in the supplement Mutants in Avalon published by Palladium Books for Teenage Mutant Ninja Turtles & Other Strangeness.
In the episode "Shredder's New Sword" of the 1987 TV series, the final battle between King Arthur's forces and Shredder's takes place outside of the castle.[1]
In the episode "Turtles in Time" of the 2012 TV series, when sent back into medieval England, the Turtles find signs giving directions to Camelot, Avalon and Savanti's tower.