Deep in the Austrian southern mountain ranges sits Pyramidenkogel, the world’s largest wooden observation tower, a “basket structure” that spirals upwards from 16 large glulam larch support pillars.
The current tower, the third tower to sit on the site, soars more than 100 metres above an 850-metre-high mountaintop, providing 360% views of the Carinthia natural surroundings from two observation towers.
For more than 70 years, a wooden tower has stood on the site, with the original, a 27-metre high rickety old tower erected in 1950 featuring a commemorative cross honouring the fallen soldiers of both World Wars, along with the tribute, “Opfer des Berges”,—Victims of the Mountain.
In 1968, a much sturdier replacement, more than double the size of the original, was erected using a mid-century “futuristic design” and for more than 40 years as a reliable observatory before being replaced in the late 2000s by the current tower.
Designed by Austrian architects Markus Klaura and Dietmar Kaden, the current tower is an impressive example of timber engineering. Working alongside the engineering practice Lackner & Raml and an entrepreneurial consortium comprised of Rubner Holzbau (wood) and Zeman (steel), the tower was constructed using more than 1,500 square metres of PEFC-certified cross-laminated timber and glulam, reinforced and supported by more than 300 tonnes of steel.
Inside, large wooden columns, elliptical rings and steel diagonal structs combine to generate the curvaceous basket-like structure, featuring three observation decks, a multipurpose glass lounge, and, for a time, Europe’s largest indoor slide – giving visitors a quick and safe return to the ground.
The elaborate wood–steel framework sits atop a concrete slab deeply embedded into the bedrock by 20-metre-long anchors. At ground level, visitors access the main structure via a masonry-built podium to accommodate public places, such as a foyer, box office, shop and restaurant.
Now more than ten years old, the tower still serves as a high water mark for the potential of mass timber as a lightweight construction system – especially for the curved load-bearing elements – both in mid-rise and high-rise construction.
- In May 2024, guests from the WoodSolutions Study Tour will visit Pyramidenkogel in the Southern Austrian mountains. For more information about the tour, click here.
