Walburg Castle, Renaissance castle in Sint-Niklaas, Belgium.

Walburg Castle is a red-brick castle in Sint-Niklaas, built in 1553 as a moated water castle. A tall, slender central tower with a pointed spire rises between lower wings with steep slate roofs and dormer windows; the left corner tower has stepped gables and stands above a brick bridge arch, its base meeting the moat water. A large bare tree stands before the central facade.

In 1550 knight Willem van Waelwijck obtained from Charles V the right to merge the lordships of der Moeren and Willemaers into the Hof van Walburg. He demolished the existing moated house of der Moeren and replaced it with the present water castle, finished in 1553 within walking distance of the market. In 1618 it was turned into a brewery; in the 19th century the Van Naemen family renovated it and laid out the park as an English garden.

Willem van Waelwijck named the castle after his wife, Walburgis, when it was completed in 1553. The park around it was renamed Romain De Vidtspark after the death of mayor Romain De Vidts, who had bought the castle for the municipality in 1949.

The castle stands within walking distance of Sint-Niklaas market, and its park, the Romain De Vidtspark, has been open to the public since 1952. The moated brick building is reached across a brick bridge arch; a large bare tree stands before the central facade. Castle and park have been protected monuments since 1975.

The castle was converted into a brewery in 1618, one of several changes of use as the property passed between owners. The moated castle was completed in 1553, within walking distance of the Sint-Niklaas market. The castle and park were registered as protected monuments in 1975.