This building in Ukraine does in fact have a gigantic, 100-foot-tall, crossword puzzle on the side. Yes, you can actually work it, though we assume if you try to do it with some rope and a can of spray paint, some guys will shoot you.
The clues are hidden around the city, and each night the answers are projected onto the side with lights.

The town did this to give people another reason to visit the Ukraine, bringing the total number of reasons up to... no, it's still at zero.