At 130 sq km, Lake Te'Nggano, in the southeast of Rennell, is the South Pacific's largest expanse of fresh water. The lake is the old lagoon floor and the tall cliffs that surround it are the old reef. Its western end has 200-odd coral islets and swamps. Four villages lie along the shore, including Te'Nggano, the subprovincial headquarters.
National Museum & Cultural CentreLocated in Honiara's town centre, this museum focuses on traditional culture and houses displays on dance, body ornamentation, currency, weaponry and archaeology. Behind it are eight traditionally constructed houses, each from a different province. There's also a small shop that sells traditional artefacts.
Mataniko FallsThe spectacular double-sided Mataniko Falls thunder into a cave full of stalagmites, swooping swallows and bats. During WWII, the cave was a hide-out for Japanese soldiers trying to avoid capture by the Americans. The trail on the way is often steep, and you might do better with a guide after Tuvaruhu (ask at the visitor information centre in Honiara).