Cube houses

These iconic houses in Rotterdam were built in the 1970 by architect Piet Blom. He had to come up with a design that allowed building houses on top of a pedestrian bridge, so with very little ground to stand on. The houses rest on a hexagonal pole and are accessible by a narrow staircase. They comprise 100 m2 living area in three levels, with beautiful views but, because of the angular design, unfortunately very little usable space (and no walls for a bookcase)