Even the armed police patrolling Madrid-Barajas airport are wary of the rough sleepers who have turned Terminal 4 into a dosshouse.
'Be careful,' a young, clean-shaven officer warned when the Mail visited this week. 'It can be dangerous here – this is zombieland.'
With an annual headcount of 65million passengers, Spain's biggest airport has long been used to human traffic.
But Barajas has now turned into a so-called 'hidden city' – thanks to the spiralling number of homeless people taking over its halls.
In the past decade, the number of rough sleepers here has swelled from about 50 people to as many as 500.
