Near the eastern side of La Pérouse Bay, there is a large oval shaped rock with many large holes. This stone formation is actually human work and is called Pu o Hiro, (holes or trumpet of Hiro). It is covered with Komari (female vulvas) designs. The name comes from the capability of blowing through some of the holes to produce a deep sound which can be heard at great distance. Today there are some Rapanui who can still make it resonate although it is difficult.
It is unique on the Island and its original use is still unknown. It was probably an instrument used to call the people, although it may also have been the centerpiece of a ceremonial site in honor of Hiro, the god of rain, since it is located in an area that is rich in monuments and petroglyphs.