Why some London Underground stations sit on hills

Long before regenerative braking was a corporate buzzword, Victorian engineers were using basic physics to save a quick buck. Many older stations in the London Underground are situated at the top of slight inclines. When a train arrives, it climbs the hill, which naturally slows it down. When it departs, it rolls downhill, using gravity to get up to speed faster. It is basically a giant, subterranean rollercoaster.