Numerous of the limestone cliffs and caves in the Bay of Phang Nga have ancient and even prehistoric paintings, such as this one, known as Khao Khian (เขาเขียน), in the mangrove area of the bay.

The drawings depict both fish and humans, as well as some abstract figures, and extend from 2000 years ago to last century.

Some of these caves are littoral, which means that they were formed by erosion of waves from the sea, but are now above sea level.