The shit that ends all shits, a crap so mean that can start the end of the days. The kind of crap that breaks one of the biblical seals letting hell loose on Earth.
Man 1: "Yesterday I went in a McDonalds bathroom and it looked like somebody took a crapocalipse"
Man 2: "What do you mean?"
Man 1: "It looked like a nuclear shit attack, it was even on the ceiling"
A large city that was once beautiful and safe that is now decrepit, crime-infested and contracting in population. A typical example would be Detroit, once the fifth largest city in America and now isn't even in the top 25. A craptropolis has hundreds of abandoned buildings, gang-infested streets, murders, robberies, carjackings, to name a few.
Hey man, wanna go to Chicago this weekend for some baseball and deep-dish?