Review on 🧩 Unravel the Wonders of San Francisco with 4D Cityscape Puzzle! by Ronald Taylor

I bought this jigsaw puzzle for our family (me, my husband and our 12 year old twins) to put together on Christmas Eve. This is an extremely difficult puzzle even for adults. It took my husband and I a few days and a lot of grumbling to finish the bottom layer (the kids gave up and left after a few hours). The second layer (foamed) arrived almost complete in the package, with several large pieces already assembled. In fact, that was a good thing, because after so much effort putting the bottom layer back together, none of us wanted to put the same puzzle back together in a different, more unwieldy material (foam). In addition, the polystyrene pieces that were still glued together were unfortunately warped so that they could not lie flat. We had to leave her for a few days with heavy objects to lay her semi-flat so we could continue assembling the rest of the pieces. Then we added buildings, which were a bit more fun for the kids, although it was also difficult to identify some of the buildings and place them in the foam's pre-cut areas. I'm still not sure I understand why this puzzle is called "4D". There is a bottom (normal) puzzle layer, a secondary (foam) puzzle layer, and then the buildings are inserted into the foam. It is flat (no relief). There is a timeline of the order in which the buildings were built. Maybe "time" is the 4th "D"?