Gadao's Cave, Ancient rock art cave in Inarajan, Guam

Gadao's Cave is a limestone cavern in Inarajan containing roughly fifty white pictographs on two stone walls. These images were made using a mixture of coral lime and tree sap applied directly to the rock surface.

A German researcher documented the cave's pictographs in 1901 and published the first scientific study of rock art in Micronesia shortly after. This early examination brought the site to scholarly attention and helped establish its importance in regional art history.

The cave is also called Liyang Gadao, and tradition credits the legendary chief of Inarajan, Gadao, with painting the images. The pictographs were painted with a mixture of coral lime and tree sap, and about fifty remain on the outer chamber walls.

The entrance is about 10–12 feet wide and 10 feet high, but the inner chamber narrows to roughly 5 feet wide, 8 feet deep and 7 feet high, so you move through it crouched or sideways. A slit at the chamber's ends leads into a cavity about 2 feet wide. Most pictographs are in the outer chamber, where you can stand and look.

Some pictographs show human figures carrying objects in their hands, but researchers have not yet determined what these items represent. These mysterious images make the cave particularly interesting archaeologically, as they suggest aspects of ancient daily life that remain hidden from modern understanding.