Fautaua Valley is a beautiful trail which passes through the jungle with wild passion fruit trees and ginger flowers. This spot is known for the 300m-high Fautaua Falls and another waterfall that naturally slides into a deep pool.
One more interesting attraction is the Lava Tubes of Hitiaa—underground galleries with a river running through them. They are long tunnels formed by the cooling and rapid hardening of lava. These tubes are located on the cliff coast on the island's east. Trekking through them requires swimming and wedging over slick rocks in the dark so you need a torch or a headlamp. On both sides of the river, you can see waterfalls and sunny bathing pools.
One of the most challenging hikes is at Mt Aorai, the second highest peak of Tahiti, through the steep rocks. Some travel guides claim it's the best climb in French Polynesia.
Hiking in Tahiti is most accessible during the dry season between May and October.