Work has started to restore a unique archway from the 14th century, which leads to the Lincoln Cathedral.
Experts will start re-roofing, repointing and structural repairs to correct settlement cracks on Exchequergate Arch.
Scaffolding has now been erected around the arch and is expected to remain in place until May.
All of the masonry will be cleaned and conservation work will be carried out to the stone carvings.
A pedestrian route through the arch will be maintained at all times during the work and the cathedral will remain open as usual.
The reverend canon John Patrick and sub-dean of Lincoln said: “Exchequergate Arch is what greets visitors who enter from the Bailgate, welcoming people to walk through and see the Cathedral in its glory.
“These works will preserve and protect the beautiful and unique Arch as well as the surrounding grounds for generations to come.
“We can’t wait for the public to see the newly restored Exchequergate Arch when the scaffolding comes down.”
Exchequergate remains as the only triple-arched gateway leading into cathedral grounds in the country and possibly all of Europe.