Biak-na-Bato National Park is located between the three villages San Miguel, San Ildefonso and Doña Remedios Trinidad in Bulacan. It offers picnic space, overnight stay and a cave guide service provided by members of the Samahan ng Mamamayan Para sa Kalikasan ng Biak na Bato, a non-government organization. This guide service was founded by volunteers from Miriam College in Manila and is now run by residents.
The caves at Biak-na-Bato are famous for their historic importance. Filipino revolutionaries used the caves as a hideout when fighting the Spanish military forces at the end of the 19th century. The group was called Katipunan, and they founded the Biak na Bato Republic on 01-NOV-1897. The pact of Biak na Bato between the Spanish Colonial Governor-General Fernando Primo de Rivera and the leader of the Katipunan, Emilio Aguinaldo, was signed in the caves on 15-DEC-1897. The Spanish government gave the revolutionaries amnesty and monetary indemnity, in return they went into exile in Hongkong. It also ended the Philippine Revolution and the Republic of Biak-na-Bato. But they later used the money to buy firearms.
Today the area is a 330ha National Park which is almost undeveloped. In the last years some improvements regarding infrastructure were made. Various caves of the park are guided on spelunking tours which always include some history.