Mauritshuis — The Hague, South Holland, Netherlands

According to what I've read, nobody's ever identified who she actually was — this is what's called a 'tronie,' a study of a face or expression rather than a portrait of a real sitter. There's apparently ongoing debate over whether that earring is even a real pearl, since a stone that size would've cost a fortune at the time.

Views across the water like this were a whole genre in Holland at the time — a way of showing off a town and the trade money running through it, according to Wikipedia. This is apparently the only cityscape he ever bothered with; nearly everything else of his is one or two people in a room.