Trent Park

The lowdown

Trent Park is a great green country estate that happens to sit at the end of the Piccadilly line. Once a private deer park, its lakes, ancient woodland, meadows and grand tree-lined avenues are now free and open to all, a proper slice of countryside on London's northern rim.

It hides a remarkable secret. During the Second World War the mansion at its heart was a top-secret listening station, where captured German generals were housed in comfort, allowed to talk freely, and bugged the whole time. The intelligence gathered from their loose conversations proved hugely valuable to the war effort.

The grounds make a wonderful free walk in any season, with woodland trails, an obelisk, a lake and wide skies. It is the kind of place Londoners are amazed to find still exists within the city's reach.