The Château des ducs de Lorraine (Castle of Dukes of Lorraine or Sierck Castle) may have been a Gallo-Roman fort, but the first historical document of the castle date from 1067. However there is probably nothing left of this first castle. The current castle was built by the archbishop of Trier in the 15th century. French army conquered it in the 17th century and since 1661 it became part of the reign of France. The castle lost its defensive purpose and it was demolished in 1673. Later fortifications was re-enhanced and left to decay several times. In 1866 The Château was acquired by the city of Sierck les Bains.
References:The Broch of Gurness is an Iron Age broch village. Settlement here began sometime between 500 and 200 BC. At the centre of the settlement is a stone tower or broch, which once probably reached a height of around 10 metres. Its interior is divided into sections by upright slabs. The tower features two skins of drystone walls, with stone-floored galleries in between. These are accessed by steps. Stone ledges suggest that there was once an upper storey with a timber floor. The roof would have been thatched, surrounded by a wall walk linked by stairs to the ground floor. The broch features two hearths and a subterranean stone cistern with steps leading down into it. It is thought to have some religious significance, relating to an Iron Age cult of the underground.
The remains of the central tower are up to 3.6 metres high, and the stone walls are up to 4.1 metres thick.