Dating from 1778, Teylers is the country's oldest continuously operating museum. Its array of whiz-bang inventions include an 18th-century electrostatic machine that conjures up visions of mad scientists. The eclectic collection also has paintings from the Dutch and French schools; a magnificent, sky-lighted Ovale Zaal (Oval Room) displays natural-history specimens in elegant glass cases on two levels. Temporary exhibitions regularly take place.