What type of rock is Sigiriya rock made of?

Sigiriya Rock is this huge plug of solidified magma, mainly made of granite. Not sure why, but it feels like a rough statement, really. It is a dense igneous rock formation that formed millions of years ago from the core of a no longer active volcano that has been deeply worn down by erosion.

It rises almost 200 metres (660 feet) above the surrounding jungle canopy, and somehow it has kept its shape through extreme weathering for ages, like millennia. The sheer vertical walls and the wide flat top made it a very good, and honestly highly defensible, place for King Kasyapa to build his famous ancient sky fortress in the 5th century.