Any naturally occurring void, cavity, recess or system of interconnected passages beneath the surface of the earth or within a cliff or ledge and which is large enough to permit an individual to enter, whether or not the entrance is located either in private and public land.
SECAL Building, DENR Compound, Visayas Avenue, Diliman, Quezon City 1100
Tel. No. 8925-2344 | 8926-8074 | 8926-2689 Trunkline No. 8929-6626 local 2055 IP Phone Trunkline No. 8249-3367 | 8248-3367 local 1186 | 1184