The most striking rock formation at Phū Phra Bāt is locally known as Uṣā’s Tower, named after the stone chamber where the beautiful princess would have been forced to live in isolation. It is a natural rock formation, restructured into a chamber with one door and two side windows standing in the centre of an open space and marked with a circular ring of vertical stones.

Some odd rock formations in Udon Thani have been the focal point of religious practices from prehistory through to modern times.