Achensee

Achensee is the largest lake in Tyrol, a nine kilometre trench of cold, clear water held between the Karwendel to the west and the Rofan to the east. It sits several hundred metres above the Inn valley, so the drive up from Jenbach is short and steep. The colour is the first thing people notice, a hard turquoise that comes from depth and mineral sediment rather than from the sky. Wind funnels down the lake most afternoons, which is why sailors and surfers use it and why swimmers rarely stay in long. Passenger boats work between the shore villages through the warmer months, and paths run along both banks.

What you actually see

• The water itself - unusually clear and cold, with the bottom visible several metres down at the shallow southern end.
• The Rofan cable car - a lift from Maurach onto the ridge on the east side, with the lake below and the Karwendel opposite.
• The lake boats - passenger services between Pertisau, Achenkirch and the southern shore, a slow way to see the walls from the water.
• The Karwendel shore - the quieter west bank at Pertisau, where side valleys run into the reserve behind the lake.

When to go

June to September for boats, swimming and open lifts. Mornings are calm; wind almost always picks up by early afternoon, which suits sailing and ruins flat water. Autumn is quiet and clear but many services stop in October. Winter is cold and grey down at lake level, with most activity moved up to the ski slopes.

Honest expectations

The water stays cool even in August, so swimming is brief for most people. The eastern shore road carries steady traffic and the villages along it are heavily built up with hotels. Parking is charged almost everywhere near the water. On windy afternoons the shore is unpleasant rather than scenic.

Nearby

Jenbach and the Inn valley lie below, and Innsbruck is under an hour away by road.