Robin Hood's activities take place in and around Sherwood Forest near Nottinghamshire, England.
"Sherwood" was initially "Shirewood" because it encompasses the entire shire, covering some 20 miles in length with various widths in various places. Giant oaks populate the forest even up until today, though few of them are old enough to have been present in the forest in Robin's day.
The irony and at the same time the reason for Robin's presence in Sherwood Forest was that it was a hunting ground for the royalty. Kings Richard I, John, Edward I, II and III regularly visited there on hunting trips. With that being the case, as Robin carried out his mission to steal from the rich to give to the poor, encounters were inevitable.