The "Gemeentemuseum Den Haag" (the Municipal Museum in The Hague) wants to change its name to Mondriaan Museum because it has the largest collections of Mondriaan paintings in the world. This is surely a good marketing idea because its current name is rather pedestrian and non-descript.
The museum has far more art (modern, fashion, music etc) than just Mondriaan, but having this focus is great.
Mondriaan is just brilliant: from evocative impressionist and pointilliste landscapes, cubist portraits to the instantly recognisable and most famous abstracts.
Here are a few of my favourite examples (all from the museum website, there are 158 works on display):