Heron tower fish tank

If you're ever find yourself taking part in an obscure London pub quiz and there's a question along the lines of 'What London office block employs three full-time divers to clean its fish tank?' you will now be able to answer without hesitation: The Heron Tower in Bishopsgate. Yup, it's true. The lobby of the building contains a 70,000-litre fresh water aquarium containing hundreds of tropical fish. Opened since 2011, the tank is Britain's largest privately owned aquarium. The three permanently on-site divers are employed to clean the tank twice a week. We didn't find out if they were pen pushers the rest of the week, only donning underwater gear for cleaning duties.

Elsewhere in Bishopsgate:
St Ethelburga's