Schloss Weilburg is the former residential palace of the Counts of Nassau-Weilburg, set on a ridge above the dramatic bend of the Lahn River that defines the town's shape. The core of the palace is a Renaissance building constructed between 1530 and 1572, with a 40-by-34-metre central courtyard; Baroque extensions added in the early 18th century extended the complex to nearly 400 metres of buildings arranged in a horseshoe around it. The Hessian state administration manages it today and offers guided tours of the interiors.
The palace gardens extend in seven terraces down the hillside toward the river, originally laid out in 1.5 hectares and later expanded to 3.8 hectares. Fountains, sculptures, and viewing terraces mark the descent, with the Lahn visible below. The orangeries at either end of the garden are among the more elegant Baroque garden buildings in Hesse.
Within the palace complex, the Schlosskirche — a Protestant Baroque church from 1707 to 1713 — is worth seeking out specifically. It is considered one of the finest examples of the type in Germany and its original furnishings are unusually well preserved. The palace also hosts the annual Weilburger Schlosskonzerte classical music festival, which has run since 1972.