The Bletchley is a spy-themed London bar where you have to crack codes to order drinks.
To do that, you use imitation World War 2 Enigma machines which generate a unique code for every "agent." Orders are then transmitted via radio to the bar.
The venue is inspired by Bletchley Park, the site where British mathematician and codebreaker Alan Turing and his team used to crack German codes during World War 2. more with video
