Rhyl, we went in the late 60s and it seemed very depressing then, wouldn’t go back anyway.
Paris, so sad about that, went many times as a student and young married with very little money and LOVED it. Went recently, full of areas of unemployed young men on the streets (no women - made me extremely uneasy), visible muggings at Sacre Coeur, beggars on the Metro and street corners. Wish I’d never gone back.
Rome - had a lovely hotel, excellent tour of the sights, wonderful weather but just couldn’t get over the traffic and parked cars! Felt so claustrophobic. And they don’t have enough money to stop most of the wonderful Roman edifices from going into disrepair.
Loved Ibiza strangely in its clubbing heyday. Never went near the clubs but the island was relaxed and beautiful. Loved New York too, been a few times recently, bustling and friendly.