I came in here to mention Rotorua. It was a cool place, but by god it stunk terribly. I was just getting used to it when I left. Upon arriving in Auckland I opened my suitcase up and a wave of stench came up off of the clothes that I had worn in Rotorua, reminding me how terrible it really smelled.
Cornerbrook, Newfoundland is quite a smelly town - I believe there is a pulp mill there.
I’ll second Mumbai, its unbelievably bad.
We were well over 20 miles offshore in a boat, and it stunk, and it has pockets of militatn stinkiness within the overall pong.
If you ever are near one of the small fishing communities that are around the waterfront of Mumbai, then this is pretty dire, hot sun, rotting fish, raw sewage.
When you get home, you have to wash all your clothes, even the ones you never wore and stayed in your suitcase in your hotel.You best bet is to buy all your holiday clothes in Mubai - they are cheap enough - and leave them all behind upon exit, this saves on packing, luggage and the chore of washing
What does “Brown” smell like? (I hope it’s brownies!)
About 50 years ago San Francisco and the Bay Area stunk. Bad. The city would barge its sewage out into the pacific ocean and dump it. The next high tide and it all came back into the bay. Raw sewage stink everywhere. Also, in Richmond the refinery at the time was Standard Oil. It would occasionally vent (fart) sulfur smelling gas. It all added up to a stinking mess.
It’s all been cleaned up now of course, but at the time… WOW!
When I was a kid, we used to spend summers at Grandma’s house in Palatka, Florida. Eventually I noticed that every time we drove over Rice Creek Bridge, Mom or Grandma would say something like, “Hey, I told you kids to change your underpants before we left!” and then everyone would laugh. It was bewildering to me because they didn’t think those kind of jokes were funny at other times.
Eventually someone explained to me that that’s where you could smell the paper mill. (I have no sense of smell).
Another joke: A Jacksonville guy and his girlfriend were on a date. They were parked, and making out pretty hot and heavy when she whispered in his ear, “Kiss me where it stinks, baby.” So he drove her to Palatka. 
Istanbul, Turkey had some sections of it that smelled like raw sewage. I don’t liked the reclaimed water smells that a lot of cities have either.
The wetlands/lagoon in Marina Del Rey can stink something awful as well. Actually, all harbors during a low tide smell pretty bad.
I clicked this thread to mention Pine Bluff, AR, but I see it’s been mentioned twice. There is nothing good about that city.
So what is it about making paper that smells so bad? I mean paper itself generally smells pretty good.
Well, I like eating cabbage or broccoli, but if you’re boiling a big pot of it, it kinda stinks. That’s kind of what’s happening at the paper mill, I think.
Tijuana, Mexico!
mystery meat sausage carts on every corner, unwashed butts, pee in the wind and four year olds begging for $ on the street at 2:00 in the morning…
This made me laugh till I cried.
Anyway, I agree with the NYC thing. It’s not just sewers, but the body odor of over 8 million people, and the smell of car emissions and not enough trees. Yech.
I also nominate Chino, CA, with its beautiful hills, lush farmland, two prisons, and wall-to-wall dairy farms. I mean, dirty, mistreated cows piled up on top of each other in concrete pens for as far as the eye can see. I went to college not too far away, in Claremont, and, boy, when it rained, it smelled like Chino. And the fact that something could over-power the smell of the smog that rolled in from LA and settled in our valley – well, that’s saying something. And I won’t even get into the flies…
Edited to add: I just realized that I was signed in as my husband. This is liberty3701, not the wonderful Jamaika a jamaikaiaké. Sorry 'bout that. Glad we agree about NYC, though.
You ain’t kidding. My dad was stationed at Subic when I was a teenager, and holy mother of all unholy -shit river is a sight and smell I’ll never forget. It was amazing how a good strong rain would flush the river clean -and then within a few days it would be putrid as ever.
I’m surprised Terre Haute, IN hasn’t been mentioned.
Yuma, AZ has that distiinct agricultural runoff smell, which I’ve also smelled in parts of the central valley (Visalia?)
The Otay industrial zone of Tijuana has some of the foulest air I’ve personally experienced, and the funk over Juarez sometimes drifts over the lower parts of El Paso on windless days.
Taipei is generally fine, except there are stinky tofu vendors all over the place. I do not care for that smell at all.
When did Greeley shut down the sugarbeet plant?
The competing aromas from GW Sugar & Monfort figured heavily into my decision to drop out of teacher-school and transfer to DU way back when UNC stood for University of No Credit. 
I grew up in Peoria, IL, where there used to be an Archer Daniels Midland plant that made malt, so people would smell that. I never noticed it much, except on rare occasions.
I live in Los Angeles, and I don’t think it smells all that bad (maybe I’m just used to it). However, the first time my parents took me to the Mid-Wilshire museum area, I was overwhelmed by the horrible stench of something that smelled like burning rubber and car exhaust. It wasn’t pollution from the traffic, it was the La Brea tar pits!
An honorable mention goes to the area around the cauliflower fields in Seal Beach, California. A field full of cauliflower is definitely a unique and pungent odor.
We just had a pretty decent storm over here, and I’m reminded again that Seoul smells disgusting when wet. We also have a whole lot of ginkgos, which doesn’t help when it’s that time of year.
Charleston, West Virginia --all the chemical-industry workings in the county that surrounds the burg, and their untrammelled dumpage of assorted effluvia into the river which flows thru town, probably have something to do with it.
St Louis, MIssouri – the whole city smells dead and rotten during a hot summer like the one I spent there.
North Richmond, Virginia.
Bakersfield, California
Amarillo, Texas
Oklahoma City, Oklahoma
Elgin, Illinois
Yuma, Arizona
Tijuana – but I like that town anyway!
Somebody already mentioned Cleveland, Ohio; it does indeed stink… As does Dayton. And Akron. And Cinncinnasty…and, oh Lord, Youngstown, the place which if you stick your nose up your ass, it will surely smell nicer than…in fact, every city in Ohio I’ve ever been to has smelled like filth and shit and miasma. It’s just a stenchy state, pretty much.
When you live here, you even get to know which parts of the city are the most recalcitrant offenders, such as the block of West 3rd Street between 6th Avenue and MacDougal. It’s a decent enough part of town, but I think there’s wetland under the street. The thing I hate the most about the smell is that it’s like a combination of sewer odor and that burning electric smell. They’re both unpleasant and seem more unpleasant together.
I must be jaded, though, because overall, I don’t think NYC smells bad, only specific areas.
Growing up in Buffalo, NY, we could smell the General Mills plant downtown, and you could tell what specific cereal they were making that day, Cheerios being the most distinctive. Even in big doses, that’s a good toasty smell.
This is, word for word, what I came here to post.
Also, I just spent the weekend in Tacoma. Man, that city is just an armpit. I do not understand why there are literally no restaurants anywhere near its Convention Center. There was a Quizno’s (closed) and according to Google, a Mcdonalds. However, when we followed the map to it, there was a smoking crater where McDonald’s used to be.