National Theatre

This is a great place to work, lots of both big and small tables set over numerous levels. Excellent food choices during the day, though the cafe stops serving at 7.30pm. Between 6.30-7.30pm it get very busy with people attending shows, but then everyone vanishes at 7.30. There are generally people working during the day, and a handful of people working in the evening, but you can stay until the building closes at 11pm without being hassled. They also don't seem to care or notice if you don't buy anything, and you're allowed to bring in outside food and coffee/soft drinks.