The Barbican in London has a long-standing reputation as somewhere you can never find your way around. The route between the tube station and concert hall is so hard to fathom that a yellow line is painted on the pavement, an Ariadne’s thread to lead you to your show. But should you think you’re grappling with a labyrinth, spare a thought for the actors and stage hands. I’ve just been on the fascinating Hidden Barbican tour and discovered that the backstage area is even more maze-like than front of house.

Welcome to London’s Barbican Centre, and the Hidden Barbican tour.

We set off  with our guide, the well-informed and charming Olga, who began by leading us through a door marked “Gentlemen’s Showers”. As someone who is used to ending up in the Barbican chair store when I’m aiming for the bar, it came as no surprise to suddenly find myself teetering on a ledge high above the theatre stage.

This was the Barbican’s fly tower, at 36 metres one of Europe’s tallest. Stretching from side to side and ranged from the front of the theatre to the back were 69 huge metal bars. From each one hung a different backdrop, automatically programmed to rise and fall. The immense space crammed with complex equipment was an extraordinary sight.

Despite the impressive machinery, I was also struck by the network of low-tech ropes draped everywhere. Olga explained that these hark back to theatre’s earliest days, when strong-armed sailors were employed behind the scenes. Nautical terminology such as rigging and breast lines (for mooring) is still used today. It was also thanks to these sailors that whistling is not allowed backstage (to find out why click here).

Our tour continued through the auditorium, past the actors’ changing rooms and down into the orchestra pit. We saw lifts and trap doors that shoot actors up onto the stage and wires that can enable them to “fly”. But perhaps the most amazing moment of all was when we stood centre-stage and the safety curtain was raised to reveal the theatre, with its rows of 1,100 seats sweeping up towards the gods. The space was vast and yet surprisingly intimate, the front seats so close they seemed a part of the stage. After years of theatre-going it was bizarre to see things from the actors’ point of view. From now on there’ll be no nodding off in a soliloquy, fidgeting with the programme or anything less than ardent applause when the curtain falls. I realise that the audience is as visible to the actors as the other way around.

Eventually we arrived at the fly tower’s summit, which has artfully been disguised by the magnificent – and little known – Barbican conservatory, its only London rival the temperate house at Kew. In among the towering palm trees and ferns, the fabulous flowers and fleshy plants, are little streams and waterfalls and cages with exotic birds. It’s much in demand for weddings but is open to the public on Sunday afternoons – which neatly coincides with the Hidden Barbican tour on that day. So after you’ve had your dose of culture you can wind down among nature. A double treat.