Much of the original station, dating back at track level to 1849 and at ticket office level to 1879, remains. It was built using London Brick to a design by George Smith (who also built Greenwich station). At the "country" end of the platforms the lines separate to the North Kent and Bexleyheath Lines. The former passes through the mile-long (1.6 km) Blackheath Tunnel immediately after the junction; the latter through the shorter Kidbrooke Tunnel after a short cutting. Blackheath Halls, run by Trinity College of Music, are close to the station.