Llancaiach Fawr Manor has been awarded a £943,200 grant, which will see its hidden attic - a former servants' quarters - opened up to the public for the very first time.
The Grade I listed Tudor mansion in Nelson, near Caerphilly, is restored and furnished as it would have been in 1645. The money will be used to improve and conserve the attraction, and also provide better access for wheelchair users.
Cllr Ken James at Caerphilly County Borough Council said the Heritage Lottery funding 'would help transform the way the past is presented to a modern audience'.
More top news
Rain clipping the far north through the evening but elsewhere staying dry with some sunny spells.
Public Health Wales figures show 25 more cases of the virus have also been confirmed.
Photos taken on Saturday morning show Roald Dahl Plass strewn with empty beer bottles and discarded canisters of laughing gas.