Pilar, is a small sea port and a second class municpality in the province of Sorsogon, Bicol Region. According to the 2000 census the town has a population of 57,898 people in 10,883 households.

Pilar is well situated for easy voyage to Masbate, Cebu, Boracay and other good beach resorts found in the south.

Though whale shark sight seeing is popularly associated with the town of Donsol, whale sharks can also be seen in Pilay Bay near San Antonio.

Interaction with the whale sharks is regulated by the local department office. With the help of WWF strict guidelines were developed to protect the sharks. These include limiting the number of swimmers per boat (six), no scuba divers and staying further than three meters from the sharks. In practise this rule is almost never applied. As many as 14 boats at a time may 'mob' a shark, with up to 30 or 40 swimmers following the shark on the surface.