Complex sentence: In the 18th century, a mansion was built but all that now remains is a huge cobbled courtyard surrounded by white outbuildings, housing an information centre and tearooms and the ruins of the old castle itself situated in the old area of the park.
Split into simpler sentences: In the 18th century, a mansion was built, but all that now remains is a huge cobbled courtyard surrounded by white outbuildings, housing an information centre and tearooms. The ruins of the old castle itself are situated in the old area of the park.