Turkey.
5* hotel but sick on the first and last nights, hassled to go into shops, hassled not to sit outside the hotel on site jewellers shop as we were apparently 'putting off customers' and taken to a shopping stop en route to the flight home 🤔
Dc visited a few years later and acquired a pool related ear infection they had to pay £300 upfront to treat. Got it back on insurance but still...
Top rated UK venue to avoid is Warwick Castle.
Absolute route-march from the car park, the one thing I'd like to have seen - the dungeons - cost an extra £9 per person to visit, whole place got progressively more rammed as the day went on and viewing the jousting was off limits due to the deafening roar of screaming massed kids.
Never again.