The Colombischlössle is a small neo-Gothic mansion built in 1859 for Countess Maria von Zea-Bermudez Colombi, an exiled Spanish noblewoman. It sits at the northwest corner of the old town, surrounded by a tidy public park, and now houses the city's archaeological collection.
The museum traces human settlement in the Upper Rhine from the Stone Age through the Romans to the early Middle Ages. Highlights include Celtic jewellery from the Magdalenenberg burial mound near Villingen, Roman glass and bronzes, and finds from local Alemannic graves. It is a manageable hour's visit and a good rainy-day option.