WatchHouse St Mary Axe

Strictly a weekday affair — doors open at 7.30am, close by 5pm and stay shut all weekend — this WatchHouse branch on St Mary Axe keeps proper Square Mile hours in the heart of the City of London. The wider group is built on coffee, design and hospitality, and the focus here is modern coffee served for dine-in or takeaway, with a wheelchair-accessible entrance for good measure. A 4.5-star rating from more than 300 reviews vouches for it.