The bathroom of a tour bus. It was an 8th grade trip to Washington DC. It was awful!
The smell coming from the grates was awful.
The kitchen! 😅
I have a friend that has a chicken coop and that thing stinks to high heaven.
Back in the 80's I used to travel through a small village in the neighboring county on my way to work. There were huge pig farms on both sides of this village. It was really ripe in the summer. Now there is only a dairy farm on the one side.
I worked in Barcelona (a lovely place) on and off in the 80s and 90s. Usually it is fine. Back then, a lot of the sewers used to run under the pavements immediately under the flagstones. If there was no wind to carry the smell away, on a hot day it could be quite "challenging", especially at weekends when everyone was home (and using the "facilities"). Not the smelliest place perhaps, but unusual in a modern, western European city.
Driving through parts of North Carolina, where many pig farms are located, in summer. Woof.
I would also give a special mention to the site of the Marine Barracks in Beirut, after the bombing, in 1983. My unit was several hundred yards from the explosion, and the stench of the smoke and carnage that lingered afterward was like nothing I have ever experienced. A horrible facet of war that goes mostly unaccounted.