The red sandstone ruins are some of the most extensive in England. The Norman keep, John of Gaunt's fourteenth-century great hall, and Dudley's late-Elizabethan gatehouse and apartments all survive as roofless shells, vivid enough that you can still read the social geography: where the king dined, where the queen slept, where the kitchens steamed.
The Elizabethan garden has been recreated from contemporary descriptions, with quartered beds, an aviary, and a marble fountain. English Heritage runs it; allow two to three hours. The view from the top of the keep takes in the modern town and the open Warwickshire fields beyond. Walter Scott set his 1821 novel Kenilworth here, which sealed the ruins' reputation as a romantic destination.