Ilmtalbrücke, Railway arch bridge in Ilmenau, Germany.

The Ilmtalbrücke is a railway viaduct in Ilmenau that crosses a deep valley using an arch structure made of prestressed concrete. The construction has two tracks for high-speed trains and presents itself as a bold, horizontal span against the rolling terrain.

The viaduct was completed in 2011 as part of the Nuremberg-Erfurt high-speed railway line. Its opening significantly shortened travel times between central and eastern Germany by rail.

The bridge is the last structure of the northern section of the new Ebensfeld–Erfurt line; south of it begins the crossing of the Thuringian Forest. An information and viewing point was set up at the Langewiesen sewage plant, and a rescue area lies under the bridge near the southern abutment.

The bridge can be observed from surrounding roads and paths that cross the valley, but it is not designed for pedestrian access on the structure itself. The best views come from the ground level in the area around it.

The three main arches span 125, 155 and 175 metres, and the bridge deck rests on them at fixed points that absorb braking forces into the ground. Expansion joints with rail expansion devices sit on the two separating piers and the abutments. The superstructure was pushed into place in 32-metre sections from both ends.