Schneppenbach was administratively tightly bound with the Schmidtburg castle, which nowadays stands within the village's municipal limits. The castle, whose beginnings go back at least as far as 929, and possibly as far as 926, is one of the oldest in the Nahe-Hunsrück region and is believed to have been the family seat of the Counts in the Nahegau, the Emichones. Their coheirs and rightful successors, the Waldgraves, owned the castle in the 12th and 13th centuries. Internal Waldgravial family disputes, however, resulted in ownership being transferred about 1330 to Archbishop and Elector of Trier Baldwin of Luxembourg. Under Baldwin, the castle was expanded, and in the time that followed, it became the seat of the Electoral-Trier Amt of Schmidtburg.
The castle was destroyed during the War of the Grand Alliance (1688–1697) by French troops in 1688. Today impressive large ruins remain.
Visby Cathedral (also known as St. Mary’s Church) is the only survived medieval church in Visby. It was originally built for German merchants and inaugurated in 1225. Around the year 1350 the church was enlarged and converted into a basilica. The two-storey magazine was also added then above the nave as a warehouse for merchants.
Following the Reformation, the church was transformed into a parish church for the town of Visby. All other churches were abandoned. Shortly after the Reformation, in 1572, Gotland was made into its own Diocese, and the church designated its cathedral.
There is not much left of the original interior. The font is made of local red marble in the 13th century. The pulpit was made in Lübeck in 1684. There are 400 graves under the church floor.