The Chinese-style bridge at Croome Court, near Pershore, Worcestershire was designed in the 1740s but was lost to decay in the late 19th century.
A £200,000 Sainsbury Trust grant enabled the National Trust to reconstruct the crossing.
The first section of the wooden bridge is in place, with the rest due to be completed by spring 2015.
Pieces of the first bridge were found in the river last year and, along with the original plans drawn up by architect William Halfpenny, they have been used to make sure the new bridge is an accurate copy.
The National Trust said: "The mid-18th century Chinese Bridge which used to span the river by Croome Court is a bit of a local legend. With only foundations remaining today, uncovered by archaeological investigations, the original bridge disappeared from the river banks leaving no photographs to record its grand scale. Thanks to £200,000 of funding from the Monument 85 Fund we're carefully reconstructing the wooden bridge which will be ready by 2015."
Also at Croome, a 'swirl' urn dedicated to the memory of the 6th Earl of Coventry was found in Home Shrubbery after lying in pieces on the ground for decades. With funding from the Friends of Croome, we're reconstructing the urn and reinstating it in the newly opened circular walk along the Home Shrubbery by late summer.
Linking the Church Shrubbery to the Home Shrubbery and Rotunda for the first time, circular walk
There is also a new scaffold climb available on the building itself.