Marigondon Cave in Cebu is a famous dive site in the Philippines because of its grand opening and labyrinthine tunnels that have claimed several lives. In 2005, archaeologists who saw the cave likened it to an underwater Tabon Cave, the most famous terrestrial cave in the Philippines. Marigondon Cave, the floor of which is presently 40 m (131 ft) below sea level, was over 100 m (328 ft) above present sea level during the last full glacial period 22,000 years before present (ybp). Human settlement remains are very likely in the cave as it would have been a prominent feature in the landscape and very attractive for habitation.

An archaeological and paleoenvironmental investigation was undertaken at the underwater Marigondon Cave offshore from Mactan Island, Cebu City, Cebu, Philippines (Figure 7.2). Global and regional sea level studies indicate that Marigondon Cave would have been above sea level during the last two full glacial periods, ca. 22,000 ybp and 38,000 ybp (Scholz 1986: 55). These two periods are congruent with the period of occupation of Tabon Cave on Palawan Island, Philippines, and suggests that Marigondon Cave may have been occupied during one or both of those periods. Initial exploration of the cave in March 2005 by divers from the National Museum of the Philippines (Batoon and Lacson 2005) confirm that silt and debris on the floor of the cave might have intact archaeological deposits beneath their surface on the sea bottom, and that the cave would have been a highly attractive locale for settlement during its periods of emergence above sea level. Its size, level floor and broad frontal exposure, are reminiscent of Tabon Cave.

During this project no archaeological deposits were found, but the work to date has:

1. identified a cave typology for the region based on Tabon Cave;
2. related sea level models and TL dating to current depth and geological stratigraphic layers to identify potential caves;
3. contributed initial characterization work plus a long-term plan to test other caves in the region.