Callao Cave is a famous limestone cave located in the Cagayan Valley region of the Philippines. It is known for its impressive rock formations and archaeological significance. The cave features several chambers, with the largest being about 200 meters long. In addition to its natural beauty, Callao Cave is notable for the discovery of ancient human remains and tools, which provide insights into early human life in the region. The cave is also a popular tourist destination, attracting visitors who come to explore its stunning interior and learn about its historical importance.