Viewers have voted for Llanelly House in a contest between three Welsh historic sites hoping to be restored to former glories.
Llanelly House, winner of the viewers' votes.
People from all over the UK voted to put one of three projects into the final of the BBC's Restoration series.
Llanelly House - a Georgian townhouse in Llanelli, Parys Mountain - a Bronze Age copper mine and Faenol Old Hall - a historic building near Bangor, competed against each other.
Llanelly House, which was voted for by more than 39% of viewers, won by a margin of only 387 votes over Faenol Hall.
It will now fight it out with nine other schemes which have won their regional heats to win a cash fund to save them from dereliction in a final at the Tower of London later this month.
The series, presented by Griff Rhys Jones, has explored historic sites across the UK
Llanelly House was built in 1714, but has since been neglected and its rich panelling and decoration has been covered up.
"The restoration of Llanelly House, one of the finest early Georgian townhouses, will be an exciting project," said Jennifer Stewart, Heritage Lottery Fund Manager for Wales.
"Not only to restore the building but to find it a long-term use which has meaning for the area.
"It's now up to the public to decide which building wins the final.'
A wide range of 30 buildings and heritage sites have been highlighted during the course of the interactive BBC series, which is presented by Cardiff-born Griff Rhys Jones.
Each venue has an " advocate" to sing its praises - Changing Rooms interior designer Laurence Llewelyn-Bowen is supporting the drive to restore Llanelly House.
Anglesey-born Euro MP Glenys Kinnock said she was "passionate" about Parys Mountain's bid, which also included regenerating the nearby Amlwch Port.
Actor Robert Hardy, meanwhile, championed the Faenol Old Hall.
The final will be held at the Tower of London later this month.
Restoration is screened on BBC 2 on Tuesday 9 September at 2100 BST.