Doppelreiterwarte (Wolfsbergkogel Lookout Tower)

The Doppelreiterwarte is a roofed wooden lookout platform at 919 m (3,015 ft) on the Wolfsbergkogel, directly on the Bahnwanderweg, the waymarked railway hiking trail that follows the Semmering Railway. The regional tourism board, Wiener Alpen, lists it as freely accessible at all times. The shortest approach is from the Wolfsbergkogel halt on the line itself, a walk of approximately 15 minutes on a forest path.

This is a long-lens viewpoint. From the railing the view runs west-northwest (bearing approximately 293 degrees) over the Adlitzgraben valley to the stone arches of the Krauselklause Viaduct, approximately 1.4 km (0.9 mi) away. Further along the same line of sight, approximately 1.8 km (1.1 mi) out and at a bearing of approximately 283 degrees, sits the two-storey Kalte Rinne Viaduct. Railjets, regional trains and freight all appear on these structures, small against the forested slopes, so binoculars or a 400-600 mm equivalent lens make the difference between a train and a speck.

The 20-Schilling-Blick, a separate and already listed viewpoint, lies approximately 400 m (0.25 mi) west on the same ridge and frames the Kalte Rinne Viaduct alone, much closer. Visiting both on one walk is the natural plan: the tower for the wide panorama and the Krauselklause, the 20-Schilling-Blick for the classic single-viaduct composition.

The tower stands just below the 961 m summit of the Wolfsbergkogel, in mixed forest above the resort of Semmering. The platform gives a 360-degree panorama that local descriptions name peak by peak: the Rax plateau and the Polleroswand cliff, the Schneeberg (2,076 m / 6,811 ft, the highest mountain in Lower Austria), Breitenstein, the Kreuzberg and the Weinzettelwand on one side; the Sonnwendstein, Hirschenkogel and Semmeringkogel with the resort itself on the other.

The railway is part of that landscape rather than in front of it. The line hugs the far side of the Adlitzgraben, disappears into tunnels and reappears on its viaducts: a railway built into the mountain rather than across it, and now a UNESCO World Heritage Site. Below the ridge stand reminders of the resort that the line created, including the former Kurhaus (1907-1909) and the grounds of the Südbahnhotel.

Cloud can sit in the Adlitzgraben while the ridge is clear, or roll in from it: check the view from the halt before committing to a long wait with a heavy lens.

The Semmering Railway was built between 1848 and 1854 under the engineer Carl Ritter von Ghega and is regarded as the first mountain railway in Europe built with standard gauge. Across its 41 km (25 mi) from Gloggnitz to Mürzzuschlag it overcomes a height difference of 460 m (1,509 ft); over 60 % of its length the gradient is 2.0 to 2.5 %, and 16 % of it has curves as tight as 190 m in radius. New survey instruments and new locomotives (the Engerth type) had to be developed to work it.

Both viaducts in view date from that original construction. In 1998 the line became the first railway inscribed on the UNESCO World Heritage List. The view of the Kalte Rinne Viaduct from the neighbouring ridge became famous enough to be printed on the Austrian 20-schilling banknote, which gave the 20-Schilling-Blick its name.

The tower's own construction date and height are not given by any official source; they are left out rather than guessed.

Most Semmering viewpoints frame one structure. This one is a roofed platform with a full 360-degree panorama that puts two of the line's original 1854 viaducts, the Krauselklause and the Kalte Rinne, on a single sightline, inside a mountain view that runs from the Rax to the Schneeberg. Its roof also makes it a useful place to wait out a passing shower.

It is reached on foot from a halt on the very railway it overlooks, and it is free and open at all times according to the regional tourism board. Combined with the 20-Schilling-Blick 400 m away, it gives two genuinely different pictures of the same UNESCO line in under an hour of walking.