Laguna del Diamante: Mendoza's High-Altitude Gem

Laguna del Diamante sits at 3,300 meters (10,826 feet) above sea level in the Argentine Andes, 220 kilometers southwest of Mendoza city. The lake's mirror-like surface reflects the 5,323-meter Maipo volcano, creating a diamond-shaped image that gives the reserve its name. Access is only possible during the summer season, typically from January to April, when the gravel road is cleared of snow. The reserve opens daily from 8:00 to 19:00, and entry requires a prior online reservation.

Getting There and Practical Logistics

Location and Access Route

The reserve lies in San Carlos Department, at the foot of the Maipo volcano. From Mendoza city, take National Route 40 south to the town of El Carmen de los Andes, then follow Provincial Route 98 for 64.6 kilometers of dirt road to the lake. The drive takes about four hours from Mendoza. The last 64.6 kilometers are unpaved and maintained by the provincial roads department; conditions vary, and a high-clearance vehicle is recommended. I found the road particularly rough in the final 20 kilometers, where washboard sections can slow you to 30 km/h.

Entrance Fees and Reservations

You must reserve online before your visit through the Mendoza Protected Areas System website (mendoza.gov.ar/areasnaturales) or the "Mendoza por Mí" app. The entrance fee for foreigners is 700 Argentine pesos (about US$5), while Argentine residents pay 400 pesos. Fees are subject to change — check the official site for current rates. The reserve limits daily visitors to 200 vehicles, and spots fill quickly on weekends. I recommend booking at least three days in advance during peak season.

Best Time to Visit

The season runs from January to April, with the road typically passable until the first heavy snowfall in late April. January and February offer the most stable weather, with daytime temperatures around 15°C (59°F) and chilly nights near 0°C. March brings fewer crowds and golden landscapes. Avoid visiting during storms: the road can close suddenly, and snow is possible even in summer. I visited in late February and encountered strong winds in the afternoon — bring layers and windproof clothing.

What to See and Do at Laguna del Diamante

The Lake and Volcano Views

The main attraction is the lake itself, a 14-square-kilometer body of deep blue water framed by volcanic scoria fields. The classic photo spot is on the eastern shore, where the Maipo volcano reflects perfectly on calm mornings. I suggest arriving before 10:00 for the best light and calmest water. The reserve also protects herds of guanacos, Andean foxes, and bird species like the Andean goose and the crested duck. Bring binoculars for wildlife watching along the western shore.

Hiking Trails

Four short trails start near the ranger station. The Sendero Mirador (1.2 kilometers round-trip) climbs to a viewpoint over the lake and takes about 40 minutes. The Sendero Laguna Este follows the eastern shore for 3 kilometers, offering close-up views of the volcano. Two longer trails (4 hours each) are designed for campers and lead to less-visited areas. Hiking is allowed on the east, south, and west shores, but the intangible zone on the north shore is off-limits to protect nesting birds. I found the Mirador trail the most rewarding for its panoramic perspective.

Camping and Fishing

Camping is permitted in a designated area near the ranger station, with basic toilets but no running water or electricity. The camping fee is 300 pesos per person per night. Trout fishing is allowed with a license (available online for 500 pesos), but catch-and-release is encouraged. The lake is stocked with rainbow trout, and fly fishing is popular in the early morning. Note that campfires are prohibited, and you must pack out all trash.

Facilities and Safety

The reserve has public restrooms at the ranger station and the camping area, but no food or supplies are sold on-site. Bring at least 3 liters of water per person, high-energy snacks, and a first-aid kit. Altitude sickness is a real concern: at 3,300 meters, you may feel short of breath. Spend a day acclimatizing in Mendoza (750 meters) before driving up. The weather can change rapidly; carry a windproof jacket, sunscreen, and sunglasses. Cell phone service is unreliable, so download offline maps before leaving.

Frequently Asked Questions

Do I need a reservation to visit Laguna del Diamante?

Yes, all visitors must reserve online in advance through the Mendoza Protected Areas System. The daily quota is 200 vehicles, and entry is not allowed without a confirmed reservation. Book at least three days ahead on weekends.

Can I visit Laguna del Diamante without a tour?

Yes, independent visits are allowed with a prior reservation and a high-clearance vehicle. The 64.6-kilometer gravel road is usually passable for 2WD cars in dry weather, but 4WD is recommended. Tours from Mendoza cost around US$285 and include transport and a guide.

What is the altitude of Laguna del Diamante and is it safe for children?

The lake sits at 3,300 meters. Children over 6 years old generally adapt well, but watch for signs of altitude sickness such as headache or nausea. Spend a night at a lower altitude before ascending, and keep the visit short if symptoms appear.

Is swimming allowed in the lake?

Swimming is not permitted; the water is extremely cold (around 8°C even in summer) and the reserve prohibits water contact to protect the ecosystem. You can wade at the edge, but stay within the marked areas.

What should I pack for a day trip?

Bring layers (temperatures can drop from 15°C to near freezing), windproof jacket, sunscreen, sunglasses, hat, gloves, 3 liters of water per person, high-energy snacks, and any medications. A high-clearance vehicle and a full tank of gas are essential, as the nearest fuel station is in El Carmen de los Andes.