District of the London Borough of Camden.
Agar Town (also known as Ague Town, Hagar Town, Agar-Town and Agar-town) was a short-lived area of St Pancras in central London. It was named after William Agar, a wealthy lawyer who lived at Elm Lodge, a villa in large grounds near to the Regent's Canal roughly where Barker Drive is now. Agar Town consisted of low-quality housing for poor people, built of the lowest quality materials on 21 year leases, and was generally considered a slum, although this designation has been questioned.
More information on the Wikipedia page [1]. The Hidden London page is [2]