Most of the monuments are built in the lovely soft local stone known as tuffeau.
They also carved figures in stone known as petroglyphs.
The exposed piece of rough usually becomes the bottom of the stone, known as the pavilion.
It is the only survivor of three such stones known as the Three Boys.
This is the site of several extensive quarries which for many years supplied building stone, known locally as keystone.
By the 8th century, however, the stone, popularly known as the "stone of visions", was taken down and broken up.
Some moai have hats of red volcanic stone known as Pukao.
Sharp stones, known as Clovis points, also were found at the site.
These were usually of a stone known as French burr.
The arch of the bridge was made of local stone known as tenelija.