| Your weekly Londonist roundup, featuring our best articles from the past seven days. The purple line's etymology explained. Belting beer gardens, craft beer havens and live jazz. Heard of Wheelmap? Trains, Vikings and chocolate in a charming city. Including tube staff on one of those days. Bishopsgate Institute wants YOU! Only one place on the map where it's possible. Wow, the Beatles played EVERYWHERE. Hold London in your palm. Time to change the rules? Four floors of Africa-centric culture in Southwark. They're very, well, attractive. Stock up on animal feed when you arrive. Explore the city's gullies, gunnels and snickets. Bloomsbury university opens to public. | 