telegraph equipment. Each of the two main entrances was protected by offset double bomb-proof and gas-proof doors. To provide evacuation for staff in case the defences failed, a covert emergency escape route was provided by granite steps cut into a steeply rising fifth tunnel leading from the rear cross tunnel to a concealed exit in the fields above. Each of the main tunnel interiors was that of a windowless open-plan office constructed as a building shell within the granite void, complete with a pitched roof to collect water seepage from the rocks, a false ceiling, plastered and decorated walls, and all the necessary services. In total about 15,000 tons of rock were removed to construct the tunnels. The construction work progressed relentlessly day and night, taking nearly a year, and the completed tunnels were opened in May 1941 by Lady Wilshaw who was the wife of Sir Edward Wilshaw, Chairman of Cable and Wireless at the time. The concrete defences around the tunnel entrances and the nearby buildings were camouflaged with the help of a local artist< the design, when viewed from the air with some imagination, resembled a belt of trees, complete with rabbits and birds. The tunnel environment being secure, dry, and at a virtually constant temperature proved to be ideal for the sensitive telegraph equipment and it continued to house the subsequently upgraded equipment after the war until the cable office closure in 1970. It was then used for training facilities for the Engineering College until the college itself also closed in 1993. Today the tunnel houses exhibits of, and is itself an exhibit of, the Museum of Global Communications, operated by PK Porthcurno. Porthcurno coastal area The cliffs and coastline around Porthcurno are officially designated Areas of Outstanding Natural Beauty. Part of the Cornwall Area of Outstanding Natural Beauty (AONB) and widely considered as some of the most visually stunning in the United Kingdom. Porthcurno beach and bay enclosed by the Logan Rock headland has been listed among the ten most beautiful bays in the World. The cliffs are enjoyed by walkers using the many public footpaths in the area and the protected South West Coastal Footpath passes through the area often within just a few yards of the clifftops. Coastal areas around Porthcurno, including those formerly owned by Cable and Wireless, are now owned, preserved and maintained by the National Trust and the remainder by