Madlum Inc. Ecoventures

"Sitio Madlum of Barangay Sibul, San Miguel, Bulacan is located at the northern part of Biak-na-Bato national park. The place was given the name, Madlum, meaning dark, because of its famous caves."

(Source: http*//communityreach*50webs*com/MADLUM
*html)