Basel Cathedral was built between 1019 and 1500 in Romanesque and Gothic style. The cathedral obtains its recognizable red colour thanks to the red sandstone used for its construction. The old Catholic church became Protestant during the 16th century.
The Synagogue of Basel first opened in 1868 and was constructed by the architect Hermann Gauss. It is modelled after the synagogue in Stuttgart with neo-Byzantine, Moorish, and Romanesque stylings. In renovations, the synagogue has been enlarged, a second dome has been added, and the walls have been painted grey before being recently restored to colour.
The Fridolinsmünster was founded as a collegiate church of the Säckingen women's convent. The convent church was built in Romanesque style, then rebuilt in Gothic style after a fire in the 14th century and renovated in the 17th and 18th centuries with elements of Baroque style. Today it is the main church of the Catholic community of Bad Säckingen.