Doesn’t have to be a city, although that would be the natural answer.
I have a bunch but if I had to choose, it would be Mumbai. That was years ago though hopefully that has changed.
Very close to Mumbai is New York, Washington D.C, Bali, and London
Jakarta, Indonesia.
San Francisco! I was grosssd out even wearing my shoes in our hotel room from all of the pee everywhere
Sicily (Catania) was shocking to me. So much beautiful old architecture in disrepair, plastered with graffiti, trash and the smell of piss and cigarettes. In contrast southern Spain which is also one of the EU’s economically weakest areas feels spotlessly clean a lot of the time and so much better taken care of.
San Francisco
Kolkata
Was also going to say this. Not sure why you had been downvoted. Calcutta is by far the dirtiest place I’ve been.
San José, Costa Rica. Trash everywhere in a way I’ve never seen before…
Siem Reap
Your mom’s coochie.
(Just kidding.)
San Francisco.
Paris and India
Jamaica had lots of garbage/litter. Stream clogged with it (2019). Obvious human trafficking. Paris stunk like piss and the subway dirty. Throw in the gypsies using kids to beg and pickpockets and you have to squint to see the beauty that is there. (2017).
Public restroom off the highway in Morocco. Poo on the walls, on the ceiling, pretty much everywhere but the hole in the ground.
What about Goa?
The most dirty place I’ve visited was a Toi Toi near a huge mountain parking lot. For luck, holding air for a minute is not an issue for me.