I visited this WHS in February 2015. The Art Rotterdam Fair was scheduled to take place on 5-8 February so I seized this opportunity to visit the interior of the Van Nelle Fabriek while enjoying the fair. Otherwise, the only way to visit the interior is by visiting during the Open Monuments Day (2nd weekend of September), on the National Architecture Day (last weekend of June), or you can reserve a group tour for 100e via Archiguides. I got a discount by booking over the internet and instead of paying an extra 10 euros for parking, I parked my car for free just a few meters away from the factory. It must be said that this WHS is best viewed from the outside to take in its architectural value. The interior is practically empty and only some signs and old machinery remain from the sections dedicated to the tea, coffee and tobacco industries. The highlights of the interior to me were the several "mushroom columns" and tall windows. Strangely enough, the columns reminded me of the Great Hypostyle Hall columns of Karnak. If truth be told though, there isn't much to see inside and the tall windows and columns can be easily seen and appreciated from outside just the same. Should I be anywhere around Rotterdam at night time in the near future, I'll surely make a stop to take a couple of photos as it seems to be much more photogenic at night.