Laguna del Maule

Laguna del Maule sits at about 2,200 metres in a volcanic complex on the Argentine border, surrounded by lava domes and flows of rhyolite and obsidian - the black glassy rock is scattered across the ground and was traded widely in prehistory. What has made the site internationally significant is movement: satellite measurements since around 2007 have recorded the ground surface rising at rates among the highest measured at any volcano on earth, consistent with magma accumulating a few kilometres down, and it is now one of the most closely monitored systems in South America. The road over the Pehuenche pass runs past it.

What you actually see

• A lake in a volcanic complex - at about 2,200 metres on the border.
• Obsidian and rhyolite flows - black glass scattered on the ground.
• Ground rising since about 2007 - among the fastest measured anywhere.
• Close monitoring - one of South America's most watched systems.

When to go

December to March; the pass road is closed by snow in winter. A full day.

Honest expectations

The road up is long and the pass is exposed - conditions change fast and the road closes. There are no services near the lake. Wind is severe. This is a geological site rather than a scenic destination.

Nearby

The Pehuenche pass to Argentina is above; Talca is down the valley.