In Sussex people will be able to visit again the houses at Standen, Nymans, Petworth, Bateman’s, Alfriston Clergy House, Monk’s House and towers of Bodiam Castle.
In Surrey the houses at Polesden Lacey, Hatchlands Park, Clandon Park and Leith Hill Place will reopen.
Staff and volunteers have been working hard behind the scenes to get properties ready to reopen safely with social distancing in place.
Trust officials say that some small properties or rooms which can’t accommodate social distancing will reopen later once Covid restrictions are lifted further or when repair or redisplay work is completed.
National Trust director general Hilary McGrady said: “This is a big moment that we have all looked forward to for months as we welcome people back safely, to spend time together at their favourite properties.
“Hundreds of our parks, gardens and countryside locations have already reopened, but we know how much our members and supporters have been looking forward to returning to see our houses and collections again.
“Our places are nothing without our visitors there to enjoy them.
“It is a matter of huge relief, pride and gratitude that the places in our care can start to reopen following closure due to the pandemic.
“Not a single place will be lost to the public. The cultural treasures that are our shared inheritance are waiting – for everyone.”
At Standen House in East Grinstead, a new exhibition will open in the house on May 29 with works by celebrity makers.
‘Joy is in the Making’ looks behind-the-scenes at the crafter, sharing their masterful works and the inspirations, emotions and deep sense of wellbeing that comes with the creative process.
The reopening of houses also coincides with the National Trust’s focus this year on its collections and the one million items it looks after, with many properties featuring in a new book celebrating 125 treasures in the charity’s care.
Celebrated works from the book include an Italian-Byzantine triptych of The Virgin and Child Enthroned with Saints, at Polesden Lacey in Surrey, painted in egg tempera and gold.
The hinged ‘wings’ of the triptych were designed to close in order to protect the interior images when not in use for prayer.
Sussex’s Petworth House has in its collection a 1AD statue of the Roman Emperor Nero.
The sculpture was acquired by Charles Wyndham, 2nd Earl of Egremont in Italy in 1763 to add to his collection of antiquities.
Also on show at Petworth House is the first globe in England. The Molyneux Globe dates from the 16th century and has been at Petworth since at least 1632.
Monks House will feature recently conserved furniture, owned by Virginia Woolf and painted and decorated by Vanessa Bell and Duncan Grant.
One of the artefacts featured in the National Trust’s new book 125 Treasures hangs in the parlour at Bateman’s in East Sussex: an orange tree embroidery, attributed to May Morris, who was William Morris’ daughter.
Hilary McGrady added: “We could not reopen so many of our places or carry out essential conservation without the patience and support of our members, visitors, donors and government schemes throughout this pandemic.
“And we are enormously grateful to our volunteers for the roles they have played, and will be playing again, as they return to our properties.
“We are also enormously grateful for the support we have had from public-funded schemes.
“All the support we have received has made the difference to the National Trust being able to continue its work and ensure that our places remain here for everyone to enjoy.”
Entry arrangements for houses will vary and people are being urged to check www.nationaltrust.org.uk