Since World War II, rumours circulated of a secret room in the Rock of Gibraltar. For years, people explored the Rock's cliffs, tunnels, and caves, but to no avail. However, in late 1997, after searching for more than two years as a team, the Gibraltar Caving Group unearthed a secret complex in close proximity to Lord Airey's Battery at the Upper Ridge of the southern end of the Upper Rock Nature Reserve. The group had evaluated potential locations of the complex, and come to the conclusion that it had to be located high up on the Rock in order to command good views of both the Mediterranean and the Bay of Gibraltar.