Biak-na-Bato National Park is a protected area of the Philippines located almost entirely within Barangay Biak-na-Bato in San Miguel, Bulacan from where it derives its name. The park also extends to the nearby municipalities of San Ildefonso and Doña Remedios Trinidad covering a total area of 2,117 hectares (5,230 acres). It was declared a national park in 1937 by President Manuel L. Quezon by virtue of its association with the history and site of the Biak-na-Bato Republic. The park consists of a cave network and a system of rivers and trails of both historical and ecological importance. Situated only 80 kilometers (50 mi) northeast from Manila, it is fast becoming a popular weekend eco-adventure destination for the city dwellers.