The Back Staircase is in part of the North wing added in the 1730s. It became opened to the public in 1925, after the Booth collection of birds was put on display, to relieve congestion, as between 3,000 and 4,000 people often visited on Sunday afternoons. It is accessed on the ground floor from the Collectors Room and on the first floor from the Towneley Room and the Burnley Room. On the second floor it gives access to the Sanderson Gallery. There is a display case in the wall on the ground floor. Bill the Bear is displayed on the first floor. A collection of long case clocks is displayed on the second floor landing.