Find puzzles and solution games at Target.com! Your puzzle fan will love this 4d cityscape washington dc time puzzle. It recreates washington dc's world-famous skyline, not only in 3-D, using scale-model buildings, but also along the 4th dimension of time. the base of the puzzle is a traditional 2d jigsaw puzzle that forms the city's street layout. While constructing the base map, your child will learn about the city. Once the puzzle base is complete, the vertical building of washington dc begins by placing 57 replica buildings in chronological time sequence. This is done by following the enclosed 4d time poster.