Right in the most central center of town, is the huge complex of the Hopital Civil. It's big, and it's old, very old. Legend says it was founded by Duke Attic (St Odile's father) in 675 AD. But the first written proof dates from 1119. Old. Nowadays, most existing building were built around 1718. On my photo, one of the entrances to the complex, the Spitaltor, or hospital gate. The chapel you see on the side is 'new': 1428.
Several other hospitals in Strasbourg, all of them much newer!