Spend the evening at His Majesty's prison and fortress: The Tower of London. Predating the modern financial centre surrounding it, the Tower of London was built to protect the city from attack, it has been home to medieval kings and queens as well as a notorious prison.
The White Tower dates back to 1080s and can host stunning dinners and receptions within it's historic walls. The New Armouries, can also host dining and receptions of up to 240 or 300 respectively. Guests entering the Tower will be guided by yeoman warder and private viewings of the Crown Jewels can be requested by groups.