Hollytrees is a handsome 1718 Georgian townhouse on the edge of Castle Park, now run as a free museum of three centuries of Colchester domestic life. The collection is small and engagingly local — toys, costumes, kitchen equipment, photographs of long-vanished shops — and the period rooms work well as a quick counterpoint to the Roman heaviness of the castle museum next door.
The house itself is worth the visit even without the displays: a generous staircase, plaster ceilings, and original sash windows looking onto the park. Allow about an hour. Free entry, closed Mondays.