As others have said, don't use Legoland. It's an over priced theme park, not a landmark.
Stonehenge is a good choice. It's a world heritage site. Here's a couple of links:
Legoland is NOT a landmark! It's a theme park. There's a LOT of difference!
There are hundreds of fascinating landmarks in the UK - all equally as interesting as Stonehenge.
Famous landmarks to visit in UK
Royal Pavilion in Brighton
St Michael’s Mount in Cornwall
Minack Theatre, Cornwall
The Tower of London, Edinburgh Castle, Hadrian's Wall, Winchester Cathedral, Glastonbury Tor, the White Cliffs of Dover, Fingal's Cave, Buckingham Palace ...
Why don't you google "famous landmarks in the UK"? Legoland is NOT one.
Legoland is an attraction not a landmark - I'm not going to do your homework for you, just google landmarks in the UK and work it out for yourself
Visiting UK ? Then here are famous landmarks and places to visit.
Minack Theatre, Cornwall
St Michael’s Mount in Cornwall
Royal Pavilion
Legoland is NOT a landmark, it's a theme park. I think you should look up the definition of 'landmark'.
Look up the Giant's Causeway. It's a site rich in mythology and geology, and is a UN World Heritage site. Also, being in Northern Ireland, most people don't even realise it's part of the UK. That's bound to win you some extra points for going off the beaten track.
Legoland is not a landmark
the houses of Parliament
stone henge
tower bridge
the london eye
the gherkin
buckingham palace
the angel of the north
hampton court palace
windsor castle
wembley
i wouldn't class legoland as a famous landmark. Pick a landmark - stonehenge would be fine - and then do some research on it. We're not here to do your homework.