I guess that it stinks because it's the waste stuff that your body doesn't want, same as why **** smells but the liquid version. I don't think anything can beat the staircases in multi storey car parks for honking of piss though.
Ammonia its in yer piss so someone must have marked their territory - probably due to a late bus which happens regularly now after deregulation by the tories
They got rid of the one on Washington road for some reason for the new Lidl store most likely. But must agree most stunk off piss mate.
Urine has no chemical formula because it is a "combination" of things. It contains water, which you know is H2O, urea, which is (NH2)2CO, sodium chloride, which is NaCl, and a number of other dissolved salts and organic compounds.
I always thought bus stops had drunks and tramps in them. I'm pretty sure drunks and tramps have a lot of piss in them. I believe piss has ammonia in it, failing that it's waste product so it makes sense it would smell.