De Gerlache Castle

Original country house built by the Ghent architect L. Roelandt who owned the old "Goed ten Ast" in 1834 and drew the plans for his country residence on the south side of it. According to the land registry archives, it was completed around 1850. Subsequently adapted several times, including around 1900 and in 1920 by the then owner, the Ghent industrialist G. Van Oost. Current condition is the result of renovations in 1958 designed by architect F. Bonaert.
Castle with appurtenances including a belvedere tower and greenhouses beautifully planted on the slope above the stream valley with a landscaped rose garden to the west and a park with ponds in landscape style, accessible via a gate on the Korte Aststraat, connected to the Lange Aststraat with monumental closure with iron chains between square pedestals with garden vases. More recent entrance gate on the village square of Mullem (Oudenaarde).
(Immovable Heritage Inventory)

Kasteel de Gerlache, also called Kasteel den Ast, is a castle in the Belgian borough of Mullem just on the border with Huise.

The building was built in the early 20th century by Georges van Oost in a French style and has a mansard roof. During the First World War, a watchtower was built on the domain. An old chapel, which was a well-known place of pilgrimage until the French Revolution, has been incorporated into a corner of the castle wall. There is also a chicory dryer present, which is why the castle is also called den ast.

Source: Routeyou

The "de Gerlache" after which the castle - officially called "Den Ast" - is often called is Gaston de Gerlache, mayor of Mullem for 3 legislatures, but above all an explorer.
In 1957-1958 he led the second Belgian expedition to Antarctica, 60 years after his father led the first with the Belgica. During this second expedition, in which the Polarhav and the Polarsirkel took them to Antarctica, the King Baudouin base was established there.

During the next expedition, led by Guido Derom, a 2,400 meter high mountain in Antarctica was named after Gaston de Gerlache.

Another fact about the castle: an emperor penguin, Hans, brought along from the expedition, who was housed in the Antwerp Zoo, was given a place in the castle after his death.

Sources:
Wikipedia
kruisem.be/kasteel-de-gerlache-huise