The people of Lvov City in Ukraine decided to add another attraction for visitors. In this artistic project it was decided to place a giant 100' (30 meters) wall on one side of the multi-stored residential houses.
There is one interesting detail about the design of the puzzle. It looks like a blank puzzle by day, but at night when special lights are on the words, the finished puzzle becomes visible.
The questions for this crossword puzzle are located in different point of interests of the city, like monuments, theaters, fountains etc. Visitors walking around the city can try to answer the questions and write down the answers. When night comes to the city they can meet at this house and check their degree of intelligence.
Very clever indeed! via english russia