In Benidorm, Spain, the developers of a 20-story skyscraper decided the building would be even better if it were 47-stories instead!

The Intempo Skyscraper was designed to symbolize hope and prospertiy.
Designs were drafted, construction began, and then somewhere along the way, the builders realized something - they forgot to expand the elevator shafts leaving the top floors unreachable except by stairs!
ViralRead suggests a better solution for top floor tenants:

Would also save on parking costs. (source: Scientific American)