When designing a penthouse apartment in Guadalajara, Mexico, architects Jorge Luis and Hernandez Silva decided to convert an old elevator shaft that never had its lift installed into a bathroom.  The toilet was placed over a floor of reinforced glass which gives anyone using the bathroom  a clear view down the 15 story elevator shaft.  Pretty neat but I am sure many guests would request a different bathroom.  At least there is not a working elevator shooting up and down the shaft.  Now that would be a bit frightening.