The Caldera de Taburiente is the great geographical fact of La Palma — a collapsed volcanic crater eight kilometres across and nearly 1,500 metres deep, ringed by walls of basalt and laurel forest and threaded by streams that converge into the Río Almendro below. The national park covers the entire caldera and its rim, and the hiking here is outstanding.
The most popular approach is from the visitor centre at El Paso, with trails descending into the caldera floor. The Roque de los Muchachos ridge walk along the crater rim is the other classic, offering views into the caldera on one side and across the island on the other. Camping is permitted inside the caldera (with a permit from the park authority); spending a night inside is an experience — the caldera walls block out the surrounding sea and you feel genuinely remote, even though you are in the middle of a small island.
The laurel forest (laurisilva) that covers the caldera walls is a Macaronesian relict — a fragment of the subtropical forest that covered much of southern Europe before the last ice age. It is protected as part of the national park.