The Casino de Spa sits in the heart of the town and claims to be the oldest casino in the world, with its origins in 1763. The current building is a handsome neoclassical structure, and while the gambling rooms are modest compared to Monte Carlo, the history is remarkable.
Even if you're not gambling, the casino operates a restaurant and hosts concerts and events throughout the year. The building is worth seeing from the outside — it faces the main square where the Pouhon spring is located, and the whole cluster of historic spa buildings in this part of town gives a sense of what the 18th-century resort must have looked like at its peak.