[1] It was designed by the architect John Howison, the surveyor for the county of Durham, as a three-storey corridor plan asylum built in the Elizabethan style with 300 beds for inmates, along with a chapel and superintendent's quarters.

[2] A major extension of the hospital, designed by William Crozier Jr. using a pavilion plan in the Italianate style with 400 beds for inmates as well as adding a new chapel, water tower, stables and cottages, was built between 1875 and 1880.

[2] During demolition, contractors broke through into basement tunnels and rooms and discovered various preserved specimens taken from inmates.

[4] The site has since been developed as a science park known as NETPark which was opened by the Prime Minister, Tony Blair, in 2005.

[6] After the site had been cleared, a secure residential centre was planned for people with mental health problems,[7] but was never built.