Check out London's abandoned Tube stations - including Churchill's secret war bunker - before they open to the public

New tours of London's ghost Tube stations and tunnels will allow visitors to explore forgotten parts of the city's underground system.

This year's season of tours, held by Hidden London, will offer Londoners the chance to step inside Down Street - a former station on the Piccadilly line that was famously used by Winston Churchill as a secret bomb shelter during the Blitz.

Visitors can also tour Clapham South (another station that was used as a wartime shelter), Euston station's "lost tunnels," and 55 Broadway, the city's first skyscraper and the old London Underground headquarters.

Tours will be held on different dates at each location, with the season beginning in May 2016 and ending in March 2017, according to the Evening Standard.

Tickets will go on sale on April 20 or you can get priority booking by signing up for London Transport Museum's newsletter before April 19.

Until then, you can take a look inside the tour locations below.