Long Island, New York
Montauk is in Long Island, New York and where Percy Jackson and his mom would occasionally vacation at. This place brings memories to Sally Jackson as she claims that Poseidon brought her here before and it is also close to the sea. Percy was conceived here by Sally Jackson and Poseidon.
After Percy returns from Yancy Academy at the end of the school year, he and his mom decide to go to Montauk for a few days. During that night, there was a storm brewing and Grover turned up warning Sally about the danger Percy was in. They quickly left Montauk to go to Camp Half-Blood, being pursued by the Minotaur.