By this I mean the overstimulation of the senses that happens while you are there.
My answer is probably Old Delhi. From the sheer population density, the near-constant honking, the utter chaos on the streets, the panoply of religions and ethnicities, the myriad scents and colours that pass you by as you travel down the narrow lanes, and not least the choking air pollution, it is certain to keep you on edge, not necessarily in a bad way.
Are there other cities that come close to, or even surpass, this?
Had a panic attack walking along the street after just arriving, never had one before but fuck it was random haha.
Love Bangkok and Thailand in general though!
I love Thailand too, but I got into Bangkok late, I was hungry and just looking for food to fill my belly I was overwhelmed by all the options, smells, sounds, etc.
Bangkok is terrible when you‘re hungry & a little on edge.