Armchair historians now need not leave their living rooms to see key English sites in incredible detail.
A partnership between English Heritage and Google means sites like Tintagel Castle in Cornwall, where King Arthur is said to have been conceived, to the Cold War Bunker in York, will be able to be explored online for the first time.
People will be able to walk the corridors of the Victorian J W Evans silver factory in Birmingham and look at the detailed ceiling paintings of Antonio Zucchi at Kenwood House.
There are also 360 degree views of the Durbar Room at Osborne on the Isle of Wight and of Queen Victoria's terrace in her stately home.
More than 160,000 historical artefacts at Wrest Park, in Bedfordshire, will also be available to look at online, including a Roman sculpture of goddess Venus, and a 19th century wood and iron tower, used to change electric lights in Covent Garden market, in London.
The 17th century "Elysium" ceiling at Bolsover Castle, Derbyshire, has been photographed in ultra-high definition, while Frank Wilkin's Battle of Hastings, which hangs within the private school at Battle Abbey, in East Sussex, will now have a larger audience.
It is the first time Google Arts and Culture has worked with a heritage organisation.
Google's Street View technology was used in the project, as well as high-definition gigapixel cameras to bring the 29 historic sites to life.
Matt Thompson, head of collections at English Heritage, said: "In our new role as a charity, English Heritage is looking for innovative ways to open our sites to the public and share their fascinating stories with them.
"Now thanks to Google Arts & Culture's technology, we've been able to bring people closer to our historic masterpieces than ever before, open up our storehouses to a global audience, and showcase hitherto unseen artefacts."
Amit Sood, director of Google Arts & Culture, said: "England has such a rich, diverse, and interesting heritage – spanning literally centuries.
"English Heritage has done such an amazing job in preserving iconic art and sites, allowing us a glimpse into what life was like in a different time."
The collection can be viewed here.