Ambach Viaduct, Highway girder bridge in Herborn, Germany

The Ambach Viaduct is a prestressed concrete girder bridge on Bundesautobahn 45 between Dillenburg and Herborn, near the village of Burg. Built in 1968 by Dyckerhoff & Widmann and Wayss & Freytag of Frankfurt am Main, it is 438 m long with a longest span of 68 m. Its deck is formed by a hollow box girder.

The viaduct was built in 1968 by Dyckerhoff & Widmann and Wayss & Freytag of Frankfurt am Main as a prestressed concrete girder bridge on the A45 between Dillenburg and Herborn. It gained wider fame through the 1976 kidnapping of Hendrik Snoek, who was chained in a 52-metre-high cavity inside one of its piers; a Herborn city employee noticed paper scraps he threw out and alerted the police, and in 1978 the Münster regional court sentenced one kidnapper to 13 years.

The bridge is known beyond the region for the 1976 kidnapping of Hendrik Snoek, managing director of the Ratio consumer market and a show jumper. Two perpetrators seized him in Münster and chained him in a 52-metre-high hollow space inside one of the bridge piers. In 1978 the Münster regional court sentenced one kidnapper to 13 years in prison.

The viaduct lies between Dillenburg and Herborn, near the village of Burg, on the A45 motorway. It is a road structure with no pedestrian or viewing access, so it is seen only in passing from the carriageway; the nearest reference points are the two towns and Burg.

The hollow box girder leaves a cavity inside the piers; in 1976 Hendrik Snoek was chained in a 52-metre-high hollow space of one pier after his kidnapping in Münster. He threw paper scraps through an opening in the concrete wall, and a Herborn city employee alerted the police.