On the west side of the Netherlands, near Leiden, is a national park called, in typical straightforward manner, Hollandse Duinen. Tourists, as our family was this summer, can hire bikes in Leiden, the birthplace of Rembrandt, and cruise down the paths toward the beach in Klapwijk by the sea, and then take the “Dunes and Mansions” tour, which takes them through that national park, and past the houses of the rich and famous—well, at least the rich—before returning to the city centre.