The roof of the station, which is on the Jubilee Line extension, is concealed beneath a park, where the only hint that life goes on underground are the glass canopies over the entrance, through which daylight pierces deep into the imposing hall. Foster + Partners chose robust materials like exposed concrete, stainless steel and glass for this project, and the glass plates in front of the platforms open in sync with the doors of the trains. This looks great, but much more importantly, it’s safe.