Sigmaringen is a city in Baden-Württemberg on the River Danube.
Sigmaringen is a popular stop on the Donauradwanderweg (Danube River Bike Trail), which begins at Donaueschingen approximately 60 kilometers to the west, and hence the area is extremely bicycle-friendly.
Sigmaringen is dominated by Schloss Sigmaringen. One of the Hohenzollern houses, it stands on a rocky outcrop between the town and the River Danube. Guided tours of the Schloss are available, where English speakers are given a written guidebook to follow as the tour is in German.
Make sure that you visit the upper Danube valley, betweeen Sigmaringen and Tuttlingen. The Danube has managed to cut a beautiful, deep passage through the limestone hills. The valley is covered in forest, but the limestone outcrops appear on the valley walls.
In the centre of the valley is the monastery at Bueron - its massive! Its very hard to get a sense of its scale from the tiny village that it dominates. The best view is from the road to Tuttlingen.