Killerton is a National Trust estate north of Exeter, with a historic house, gardens, chapel, woodland, and broad parkland. It is one of the easiest country-estate excursions from the city, especially for visitors with a car.
The appeal is the full estate rather than a single room or object: walking, gardens, family space, and a house that gives context to Devon landowning life. Check seasonal opening for the house and garden areas before going.