Mount Pinatubo
The June 1991 eruption of Mount Pinatubo was the second-largest of the twentieth century and rearranged the climate of the planet for two years. What it left behind, on the boundary of Zambales and Tarlac, is a brilliant aquamarine caldera lake ringed by jagged volcanic ridges — one of the great hike-to views in Southeast Asia. The standard day trip starts at the Capas registration centre before dawn, two hours of 4x4 across a moonscape of lahar deposits, then a one-hour walk up the rim trail to the lake. Day trips run easily from Manila or Clark; aim for the dry months (December–May), and start early to be off the rim before the afternoon heat.
