The gorge was formed by glacial erosion during the retreat of the last ice age, leaving behind vertical walls up to 32 meters high.
The current wooden walkway system was originally constructed in the late 19th century and has been rebuilt multiple times to improve accessibility.
The gorge is named after Sigmund von Thun und Hohenstein, who was the governor of Salzburg at the time the walkways were first opened to the public in 1893.
The Klammsee at the top of the gorge was created by human engineering as part of the hydroelectric power development in the Kaprun valley.
The rock formation within the gorge is primarily composed of dark, slate-like limestone known as the 'Bündnerschiefer'.
Sigmund Thun Klamm is a 320-meter-long gorge carved into limestone by the Kapruner Ache river over thousands of years. The path consists of wooden walkways and bridges anchored directly into the rock faces along the narrow canyon walls. Visitors ascend through the gorge to reach the Klammsee, a reservoir located at the upper end of the path. The site features significant geological formations, including glacial striations and erosion patterns. The gorge was designated a natural monument in 1938 due to its geological significance. The wooden structures are dismantled and reconstructed annually to prevent damage from heavy winter snowfall and ice formation. Water flow through the gorge is controlled by the upstream power plant infrastructure, which impacts the volume of the waterfalls.
The highest wooden bridge at the top of the gorge, offering a vertical perspective looking down at the rushing river.
Wear footwear with strong grip, as the wooden steps and railings are frequently wet from mist and spray.
Bring a light waterproof jacket even on warm days, as temperatures drop significantly within the shaded canyon.
Combine the visit with a loop around the Klammsee lake for a complete excursion.
Attempting to traverse the gorge immediately after heavy rain, as water levels can rise and cause temporary trail closures.
Open only from mid-May through mid-October; closed during winter months due to ice and snow hazards.
