Conservation work is due to begin at a memorial to a drowned Welsh village.
Capel Celyn was flooded over 50 years ago to construct a reservoir supplying drinking water to Liverpool and Wirral.
A chapel was built on the site in 1965 to remember the families forced to move from the Welsh speaking community near Bala in Gwynedd.
The event is still regarded as a key point in movements to protect the Welsh language and devolution.
The memorial chapel was constructed using stones from many of the buildings in the village, which along with the village school, post office, homes and the original chapel, sit beneath the Tryweryn reservoir.
Last year it was given protection as a Grade II listed building by the Welsh Government's historic monuments body Cadw.
Andrew Dixon, of Welsh Water, said: "As a company we understand how important Celyn Memorial Chapel is to the people of Wales. That's why over the next few months we'll be carrying out conservation work on the chapel to preserve the building's construction and integrity.
"Over the years water has seeped into the building, and as it was built without electricity or heating, it has meant that over time the building has become damp."
The water company has been working with specialist architects and Cadw on the conservation plans, which will see the building's mortar removed and repointed, and the chapel roof recapped.
The work will take until November to complete.
"As custodians of the building we feel it's important that we preserve the building for decades to come," Mr Dixon said.