A bridge has been put up as part of the £4.6m flood defence scheme for an historic Cornish village devastated by torrential rainfall in 2004.
The bridge design was simplified after concerns from residents
About 440 million gallons of flood water poured through Boscastle, ruining buildings and washing vehicles away.
Engineers have lowered a new bridge into place above the River Valency in the last stage in the Environment Agency's defence scheme.
The river was also widened to increase capacity when water levels are high.
The existing lower bridge was damaged in the flood of August 2004 and planning permission granted for its demolition and replacement.
The replacement arrived in two pieces on articulated lorries, before being lifted into place by a giant crane.
The £400,000 bridge was built off site by Cornish Concrete Products, based in Truro.
Once in place, a temporary central support was driven into the river bed until it can be joined together and properly reinforced.
Andrew Davey, of the National Trust, said: "Today represents a significant moment in the whole project, where we can say we are finally on the 'home-run' to the completion of the scheme."
He said the "simple" design had been significantly adapted to address concerns by the community over an earlier model.
Initial plans were thrown out when residents said the structure was too large and too modern.
The altered design has been approved by North Cornwall District Council.
The Environment Agency said it had worked closely with the local community, the National Trust's architectural panel and the Boscastle Bridge Working Group to ensure the design was sympathetic with its surroundings.
During the 2004 floods, military helicopters airlifted around 100 people to safety, 58 properties were flooded and four businesses were demolished.