Hidden behind this massive neoclassical edifice is the world’s biggest and best collection of paintings and frescoes by Peter Paul Rubens. Other artists displayed here include the Flemish Primitives Jan van Eyck, Rogier van der Weyden, Hans Memling, and Pieter Brueghel, as well as more recent Belgian favorites James Ensor and Paul Delvaux. Alas this glorious gallery, normally stuffed with the loot of 500 years of great painting, is closed for restoration until 2021 so if peerless Flemish art is your addiction, you’ll have to get your fix at the Groeningemuseum in Bruges, although a few works from KMSKA are on display in the Golden Cabinet at Museum Rockoxhuis (Keizerstraat 10-12; www.rockoxhuis.be; tel. 03/201-9250).