There's an amazing museum of sculptures (modern art but not only) on the coastal part of the City called "Beelden aan Zee" (literally: Sculptures on Sea). The exposing part of the building has entirely been dug into the dunes. Only natural light comes in through parts of the roof and windows giving the sculptures (in bronze, marble, alloy, steel and other materials) an extra touch. From the main windows you just see sand while overlooking the North Sea. Their enormous collection in stunning and is worthwhile a visit. Just take the tram from the city-centre which brings you close to it. Afterwards have a stroll along the windly shore for some really fresh air but try to avoid crowdy July and August.