Reviewers who gave it three stars or less described the Tate Modern as ‘boring’ with ‘no atmosphere’, with over 1,000 people rating it as ‘poor’ or ‘terrible’.
The Science Museum, also in London, came in second on the list, compiled by language learning platform Preply.
This was followed by Blackpool Tower and the Southbank Centre, both of which disappointed 20% of those who visited.
London spots Somerset House and the Natural History Museum made the list too, as did the Angel of the North, Edinburgh Castle and Cardiff Castle.
In third place, Stonehenge in Wiltshire upset visitors with its 21% admission cost, peak-time crowds, and ‘lack of imagination’ display area.
The UK's top 10 most disappointing landmarks… Tate Modern: 23.21% disappointed visitors, Science Museum: 22.50% disappointed visitors.