Altes Schloss
You start on a rock. The Altes Schloss sits on an outcrop about 440 m above sea level, towering over the Lower Town while staying roughly level with the rest of Meersburg. It is considered one of the oldest inhabited castles in Germany, and the name simply sets it apart from the 18th-century Neues Schloss you will reach later on this walk.
Everything turns on the central keep, the Dagobertturm. One story says the Merovingian king Dagobert I built it in 630, when he was in the Lake Constance region working to Christianize the Alamanni. That version rests on a document from 1548, and it found a passionate supporter in Joseph von Laßberg, who lived in the castle in the 19th century. A charter of Frederick Barbarossa dated 27 November 1155, leaning on older and doubtful records, even claims Dagobert personally fixed the boundaries of the Bishopric of Constance.
The other story is more sober. No castle foundations around the lake are recorded for the 7th century, while the 12th and early 13th centuries saw a wave of them. On this reading the castle went up in the early 12th century and later borrowed the famous king's name. The place first appears in writing as Merdesburch in 1113. Look at the base of the keep: those huge, roughly squared stones could belong to either era, which is exactly why nobody can settle the question.
If you only pay for one interior on this route, make it this one: it is where Meersburg's story begins, and Laßberg will turn up again at the Fürstenhäusle. From here it is 270 m and four minutes down to the water.
