The old Penguin Pool is my favourite part of London Zoo. It was designed by Russian émigré Lubetkin in 1934. It’s playful and so ahead of its time: one of the earliest examples of modern architecture in London. They’ve moved the penguins now but the pool’s Grade 1 listed so it’s there to stay. If you’re anti-zoo for the right reasons, I feel you, but if you’re anti-zoo because ticket prices are high, then you can view the Snowdon Aviary or poking-out giraffe heads for free from Regent's Park just outside.
Regent's Park, The Broad Walk, London NW1 4SX, UK