If you mean “dirty” in other ways, Seoul is still very good. Crime is extremely low, thanks to it being a city that never sleeps, and even in the darkest of alleys, you won't really find yourself in any considerable risk. read more
A few days ago, someone told me when they visited Seoul, it was filthy and there were transsexuals everywhere (exact words). I doubted it a bit, but then I wondered a bit. read more