Dedicating their lives entirely to prayer, silence and solitude and leaving their cloisters only for medical appointments, the Carmelite nuns may seem to be the antithesis of the modern age.

So when they left the walls of their monastery and ventured into London, what appeared to be seven nuns standing next to the Seven Sisters station sign would have been suprised to become an internet hit.

But the timing was not lost on one commuter, who could not resist taking a photograph which has been widely shared online.