Work has begun to make a permanent opening into one of the vaulted chambers recently found in the tower supports of Bristol's Suspension Bridge.
The 12 vaults were found last year
They were discovered beneath the south tower in Leigh Woods last year, and are now being opened up permanently.
It had been assumed for more than 30 years that the supports bearing the bridge were solid stone.
In November 2002, workmen discovered two tiers of 12 Victorian chambers in the 110-feet tall south tower on the Leigh Woods side of the gorge.
Each one is connected by a network of narrow tunnels, and the biggest chambers are almost the height of three double-decker buses.
The 137-year-old suspension bridge was designed by engineer Isambard Kingdom Brunel and opened, after his death, in 1864.