Burg Rötteln is located on a hill north of the quarter Lörrach-Haagen. It is the third largest castle ruin in Baden and is considered an important landmark of Lörrach and one of its tourist attractions.

The castle is over 300 meters long and 40-80 meters wide. The outer castle with a museum and tavern is freely accessible. For the upper castle there is a entrance fee of 2 euro.

The castle was built in the 11th century by the Lords of Rötteln and documented for the first time in 1259.In 1315 it passed to the margraves of Hachberg-Sausenberg. They extended the castle to one of the largest and most powerful fortresses in southwest Germany after the severe earthquake damages of 1356. 1503 the fort came as a heritage in the possession of the Margrave of Baden.

During the Peasants' War the castle was taken and plundered in 1525 by insurgents, but not damaged. In the 30-year war it changed ownership several times and was also damaged in these battles. On 29 June 1678 it was destroyed during the Franco-Dutch War by French troops, the bastion was demolished in 1689, but some parts of the castle appear to have been used by the margrave's administration until the 18th century.

Already in 1840 there were the first actions for the preservation of the ruins, it is on the monument list of the Grand Duchy of Baden from 1901. Since 1925, the local population takes care to preserve the ruins and keep them accessible, with a small castle museum in a restored administrative building. Today the site is owned by the institution Staatliche Schlösser und Gärten Baden-Württemberg.