Sir ArthurConan Doyle bought the plot of land after his wife Louisa was diagnosed with tuberculosis. He thought Hindhead would be a good place for her to rest because of its healthy micro-climate in the South Downs.
It is thought that the author drew up the plans himself, before asking his friend Joseph Henry Ball, an architect, to finalise the design.
Conan Doyle and his wife lived there for 10 years until she died and he remarried. He wrote The Hound of the Baskervilles there in 1902 and resurrected Sherlock Holmes in 1904.
Bram Stoker, the author of Dracula, interviewed Conan Doyle at Undershaw. Afterwards he said: "It is so sheltered from cold winds that the architect felt justified in having lots of windows, so that the whole place is full of light. The picture on the right is where Bram Stoker interviewed Conan Doyle.
"Nevertheless, it is cosy and snug to a remarkable degree and has everywhere that sense of 'home' which is so delightful to occupant and stranger alike."