In a mystery story, details of setting are very important. Remember that setting is not just the time and place, but all the details of what is there.
The story takes place in London and Surrey England. At the beginning of the story, Watson notes that “the events in question occurred in the early days of my association with Holmes, when we were sharing rooms as bachelors in Baker Street” (enotes etext p. 4). This was where they lived in London. He also tells us that the story takes place in “early in April in the year '83” (p. 4). By this he means 1883. This is significant because it was an exciting point in history, at the height of the industrial revolution, when new inventions and ideas were everywhere.
A large portion of the story takes place at the “ancestral house” of the family, known as Stoke Moran “on the western border of Surrey” (p. 4). The home has been in the family for generations. It is very spooky. Although the grounds used to be extensive, now “nothing was left save a few acres of ground, and the two-hundred-year-old house, which is itself crushed under a heavy mortgage” (p. 5). The inhabitant of the house is Dr. Roylott, and he is an eccentric recluse.
Dr. Roylott has spent time in India, and that makes for one of the most interesting aspects of the setting. In addition to the general state of disrepair of the house “he has at this moment a cheetah and a baboon, which wander freely over his grounds and are feared by the villagers almost as much as their master” (p. 6). Because of Roylott’s temper and the scary animals, no servants will stay in the house. The house is old, and only one wing is used. There are also strange whistles at night.
The House is described like this:
The building was of grey, lichen-blotched stone, with a high central portion and two curving wings, like the claws of a crab, thrown out on each side. In one of these wings the windows were broken and blocked with wooden boards, while the roof was partly caved in, a picture of ruin. The central portion was in little better repair, but the right-hand block was comparatively modern, and the blinds in the windows, with the blue smoke curling up from the chimneys, showed that this was where the family resided. Some scaffolding had been erected against the end wall, and the stonework had been broken into, but there were no signs of any workmen at the moment of our visit. Holmes walked slowly up and down the ill-trimmed lawn and examined with deep attention the outsides of the windows. (p. 13)
Watson and Holmes go to the house to solve the mystery.