Lonely Planet review
The Mu'a area contains the richest concentration of archaeological remnants in Tonga. There are 28 royal stone tombs (langi ) in the area (15 of which are monumental), built with enormous limestone slabs carried by canoes either from nearby Pangaimotu, Motutapu and other parts of Tongatapu, or possibly from as far away as Ha'apai or even Futuna.
The structure closest to the main road is the Paepae 'o Tele'a (Platform of Tele'a), a monumental, pyramid-like stone memorial. Tele'a was a Tu'i Tonga (king) who reigned during the 16th century, though his body is probably not inside.
The other structure, the Langi Namoala, has a fine example of a fonualoto (vault for a corpse) on top - thought to be the burial site of a female chief - but it is also empty.
To the northeast of the two principal mounds is the 'Esi'aikona, an elevated platform used as a rest area by the chief and his family. Also nearby is the Hehea Mound, built during an enormous ancient land-reclamation project.