Neo-Manueline style. It is so close to the water that at high tide the sea comes right up to it. The palace is from 19th century and it was property of Manuel Castro Guimarães (a Portuguese Count from Cascais). He left all his property to a Municipal Museum and a traditional library.
Worth a visit to see the lovely interior furnished as the last residents left it. Also good views from the tower. Free entrance as are all the museums in Cascais. Also close to the Casa de Santa Maria and the beautiful lighthouse. There is the lovely Jardim Marechal Carmona close by too and opposite the museum a lovely restaurant overlooking the sea and the lighthouse where you can have very good sardines!