There is a heavy iron door at NDSM-Plein 78 in Amsterdam Noord. It does not have a sign. There is no doorbell to ring, no lobby to walk into, no reception desk waiting on the other side. Behind it is an elevator. The elevator rises through the steel skeleton of a monumental harbor crane, through the industrial architecture of a working monument until the doors open somewhere above Amsterdam, above the IJ, above the ordinary world entirely.