Works of art to see Luzon

It was the headquarters of the Philippine government in exile of Manuel Quezon but also of General MacArthur. Completed in 1922, the main tunnel is 250 meters long and 7 meters wide, with twenty smaller tunnels attached to the left and right. It was later equipped to serve as an underground war hospital, with over 1,000 beds. Cannons and other installations as well as military equipment are on display to the public. Night tours are possible, and there are occasional sound and light shows.