They line every inch of pavement; they queue 50 deep for every attraction; they stick to the beaten track religiously, only disappearing to dive underground and travel a single stop on tube.
You can't begrudge tourists though.
I'm the same when I go abroad. Clueless and wholly reliant on the same guidebooks as everyone else, queuing my way around Barcelona and searching out overpriced calamari along with the rest of the English hordes.
It's a shame. They (and I) miss so much that's hidden only minutes away and would be just as busy as the London Dungeon, were it not for a lack of advertising.
The Conservatory, at the Barbican Centre, is one such place.
Live in London? Been to London? Ever heard of it? No? Thought not.
As the name suggests, it's a giant conservatory sat on top of the Barbican Centre. Heated to a tropical temperature and full of plants to match, it's a miniature Kew Gardens perched high above London's main financial centre.
'Fascinating' doesn't do the place justice. Imagine a 1960s urban jungle, crawling with vines, creepers, and possibly some meat-eating flowers - a set for a post-apocalyptic movie, where global warming takes hold, and no-one can be bothered with the gardening.
And just like a post-apocalyptic city, it's a place that doesn't attract the tourists. No queue. No gift shop. No real door, that I could find, having to sneak in via a fire exit that someone had propped open with a chair.
The only really crowded part of the whole experience was the pond, where tens of the fattest fish I've ever seen, wrestled each other for food and space. I knew carp could get big, but this is ridiculous. Again, shades of the nuclear aftermath creeping back in.
Next time you visit London or are thinking of doing something touristy, if you live here already, the Conservatory in the Barbican Centre should be high on your list.
Pictures: My Instagram.
Like this? Check out more from the Hidden London series, including VauxWall and Soho Whisky Club.