kw: card stacking, records
Many years ago my first wife and I filled a rainy weekend with building a house of cards that reached the ceiling of our spare room. We thought it was really something. We used about twenty decks of cards. Wish I'd thought to take a picture. As it happens, it is nearly nothing compared to the creations of Bryan Berg, as this image shows:
This tower is 25 feet 9 inches tall. The entire structure required 1,800 decks of cards. He has built other structures with as many as 4,000 decks, that cover large areas but don't go as high. Go to this Daily Mail article for more, including a video.