De Wallen is the medieval city center, crossed by canals and narrow alleys lined with old-school bars. Surrounded by the neon-lit red-light district, the Oude Kerk is a centuries-old former church hosting cultural events. Similarly, the old red-brick stock exchange, Beurs van Berlage, now presents exhibitions and concerts. The Museum Ons’ Lieve Heer Op Solder hides an ornate Catholic church in its 17th-century attic.