Voormalige Nazorgkolonie en Sanatorium Zonnestraal by Zoë Sheng
You have to come here on a sunny day else it's pointless - not really, I'm joking, but who would visit a place called "Sunbeam" if it's not! If I would be sick and my mom would tell me "Zoe, they'll place you into the Magic Sunbeam hospital" I would probably mentally cure myself within days of anything! Jokes aside, it was a lovely weekend even though the photo filter I chose makes it looks a little gray. Most people came here to have a stop between their bike tour and enjoy lunch at the cafe. The rest of the sanitarium, oops I mean "Sanatorium" was closed but a few entrance hallways. The place has soooo many windows that you can see everything from the outside. A lovely walk. The architecture is very retro.
There should be a group of sanatoriums established one day with Paimio, Losheng, plus of course the infamous Arkham Asylum ;) Unlike these places, however, Zonnestraal is attempting to inscribe it for an iconic architecture - fair enough, although I would prefer the place then open for a visit and not be like Van Nelle Factory, so perhaps wait until it is not in use anymore or have guided visits on weekends.
The documentation is very old, 1995, and still mentions restoration work. This must have been complete ages ago because there is no sign of restoration or anything that looks out of place.
Edit: so just after writing the review the site was downgraded to "former" tentative which means there are currently no plan to inscribe this. It may come back one day but it is a long process. Seeing that the Netherlands are so compact with places to visit I still recommend a visit.