The biggest chamber in Callao Cave is around 160 feet wide and 118 feet high. And possibly because of the chamber’s grand scale, locals in the area saw fit to turn it into a chapel. Amazingly, too, this house of God – lit by that natural light traveling through slits in the ceiling – even has an altar of rock.
Yet environmental processes within the Callao Cave complex have promoted the formation of several other fascinating features within each of the chambers. Specific examples of these include cave curtains, flowstones and dripstones. And particularly within the more deep-seated chambers of the network, formations known as stalagmites and stalactites have also developed.
Both stalagmites and stalactites form from a build-up of minerals deriving from drops of water. A stalagmite specifically points upward from the ground, and its end tends to be relatively flat. A stalactite, on the other hand, points down from the top of the cave and tends to have a sharper end.