There's the 'Schmale Haus', one of the narrowest hotels in the world. They offer bed and breakfast in the beautiful and historic part of the city, located in Ulm, Baden-Württemberg, Germany.
Probably the narrowest hotel in Ulm is located in the center of the historic fishing district, with its beautiful half-timbered houses, numerous cafes and restaurants, small canals, bridges and narrow streets. It combines the charm of yesteryear with the comfort of an exclusive boutique hotels. Not least, this residence boasts "Narrow House" for its unique location, a few meters from the Danube and not far from the Ulm Minster and the pedestrian area.
The building was completely renovated in 2002 consuming and with great attention to detail, with a particular emphasis was placed on preserving the unique character of this former fisherman's house. In the spring of 2015, the entire interior of the house, including the bathrooms were completely renovated, creating a harmony between the high value of the building tradition and a modern, exclusive design with amazing interiors created. The original stucco ceiling in the entrance area, which is with respect to date of their creation time in the period to 1600, has been doing splendidly restored and now the whole house equipped with a high-quality, Italian lighting concept and specially designed furniture made of solid walnut. The aim was to combine the hotel "Narrow House" from the first moment of warmth and cosiness with accents of modern interior design.
source: [DE] Das Schmale Haus