Area
57.45 km²
Population
13,624

Weilburg is a town in the district Limburg-Weilburg in Hesse, Germany. The old town, built on and around a rocky hill almost encircled by the Lahn river, contains a castle of the 16th century, formerly the residence of the dukes of Nassau-Weilburg, and later of the grand dukes of Luxemburg.

• The castle from the 14th century, extensively rebuild in the 16th and 18th century. The so called Kernschloss (core castle) parts of the building in Renaissance style count to the best preserved Renaissance castles in Hesse.
• The Protestant Schlosskirche (castle's church) from the begin of the 18th century.
• The in Germany unique shipping tunnel from 1847.
• The half timbered houses from the 16th to the 19th Century
• The grammar school called Gymnasium Philippinum from the 18th century
• The Neptunbrunnen ("Well of Neptun") from the year 1709.
• The so called Kalvarienberg and the chapel ('Heilig-Grab-Kapelle) on the old graveyard.

Said to be unique in the world is the Weilburger Tunnel ensemble. There are three tunnels next to each other for cars, boats and trains.