A £445,000 winter programme to repair and maintain parts of the Kennet and Avon Canal has begun.
The Canal and River Trust project will see improvements made to six locations across Wiltshire, Somerset and Berkshire over the next five months.
Giant lock gates are being replaced and historic canal walls rebuilt.
The canal is an 87 mile (140km) waterway linking the River Thames at Reading to the River Avon in Bath.
Millions of litres of water will be drained from stretches of the canal and thousands of fish rehomed before some of the engineering work is carried out.
Canal and River Trust director Richard Thomas said: "The Kennet and Avon Canal is truly beautiful and the projects we're carrying out over the next five months are extremely important."
The Kennet and Avon Canal was originally opened in 1810, but gradually fell into decline after the Great Western Railway was built.
The waterway was completely restored by volunteers and officially reopened by the Queen on 8 August 1990.