Protester chains herself to Leicester's Bowstring Bridge
The woman, who called herself Karen, breached the razor wired security cordon around the Duns Lane bridge, in Leicester's West End, at 6am.
She said she had wrapped herself in chains and attached herself to a girder on the bridge, which about 40ft above the road.
Speaking down from her position, she said she had taken the extreme step because she believed demolition was about to begin today.
Police were at the scene, but officers said their guidance was to allow peaceful protest.
The bridge is being knocked down by contractors to make way for a new De Montfort University sports centre. The future of the neighbouring Pump and Tap pub is also in doubt and is to close before the end of the month.
Remaining good humoured throughout and well wrapped up against the cold, she said: "We've been doing high profile protests for weeks now, this is direct action.
"This is the final destruction of the bridge, and we can't let that happen. It's unique."
Stuart Simmonds, a member of the campaign group to save the bridge and the pub, said: "As far as we know this is the day they were going to start demolition.
"Once that starts it's game over."
Watch a YouTube video of the protest.
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