Callao Cave () is one of 300 limestone caves located in the Barangays of Magdalo and Quibal in the municipality of Peñablanca, about northeast of Tuguegarao City, the capital of Cagayan province within the Peñablanca Protected Landscape and Seascape in the western foothills of the Northern Sierra Madre Mountains on Luzon island in the Philippines. The town Peñablanca's () name refers to the predominance of white limestone rock formations in the area. First excavated in 1980 by Maharlika Cuevas, the seven-chamber show cave is the best known natural tourist attraction of the Cagayan province and in February 2020 has officially been recognized as an important cultural property of the Philippines. Fossils of archaic humans, that lived during the Late Pleistocene were first discovered in the cave and documented in 2007 by a team led by Armand Salvador Mijares from the University of the Philippines and eventually confirmed in 2019 as to belong to a previously unknown and now extinct human sub-species - Callao Man or Homo luzonensis. Protection status Callao Cave was visited by American Governor-General Theodore Roosevelt, Jr. in 1932 who under his term created the National Park system of the country with the passing of Act No. 3195 in 1932. Callao Cave was one of the earliest national parks of the country when it was established on July 16, 1935, by Proclamation no. 827. The Callao Cave National Park encompassed an area of of land. With the passing of the NIPAS Act of 1992 that revamped the protected areas of the country, the Callao National Park was reclassified but enlarged by Proclamation no. 416 on June 29, 1994. The protected area was reestablished as the Peñablanca Protected Landscape. In 2003 upon the recommendation of the Department of Environment and Natural Resources (DENR), the protected area was further enlarged to include certain parcels of land in the public domain. Proclamation 416 no. was amended by Proclamation no. 484, signed by President Arroyo on October 6, 2003. The law enlarged the park to and renamed as the Peñablanca Protected Landscape and Seascape (PPLS). The protected area is particularly described as bounded on the North and East of Public Forest under FR-1011 per Proclamation No. 584 dated July 8, 1940; on the South by Callao Reforestation Project and on the West by Block I, Alienable and Disposable of Cagayan Project No. 13-C, Certified on February 27, 1923. Features More than 300