Laguna del Diamante

Laguna del Diamante lies at around 3,300 metres in a reserve on the Chilean border, a lake of meltwater fed by snow from the surrounding cordillera, and when the wind drops it reflects the Maipo volcano, a near-symmetrical cone of about 5,300 metres rising directly beyond the far shore. Legend has it the lake's name comes from that reflection, described as a diamond in early accounts. The road in climbs through the Portillo valley, past the Refugio Militar and over a high pass, and the reserve protects guanacos, condors and high-altitude wetland. San Martín's army crossed the Andes through this area in 1817, and the route is marked in places.

What you actually see

• The volcano reflection - Maipo's cone mirrored in still water.
• The high lagoon - cold meltwater at over three thousand metres.
• The wildlife - guanacos, condors and waterbirds on the wetlands.
• The mountain road - the climb through the Portillo valley and over the pass.

When to go

December to March only; the reserve opens for a short summer window and snow closes the road the rest of the year, with exact dates varying each season. Wind rises through the day, so the mirror effect is a morning phenomenon.

Honest expectations

The drive is around four hours each way on rough gravel with steep sections, and low cars struggle. Altitude affects many visitors. There is no fuel, food or signal beyond the control post, camping is basic, and wind at the lake is often brutal by afternoon.

Nearby

Mendoza city is the departure point; the Maipo volcano stands on the border beyond the lake.