De Toonzaal is a music venue housed in the city's former synagogue, a striking Moorish Revival building from 1927. The synagogue was used during the German occupation and the building fell into disuse after the war, but was eventually restored and repurposed as a concert hall for chamber music, experimental music, and improvised performance.
The acoustics are excellent, and the restored interior — with its arched windows, decorative tilework, and gallery — makes for an atmospheric setting. The programming is adventurous, mixing classical chamber music with jazz, improvisation, and contemporary works. Worth checking the programme if you're in the city for an evening.