Not just the Detectorists tonight on BBC 4 at 10pm, but Part 1 of Digging For Britain (visiting various digs) at 8pm and The Mystery of Rome's X Tomb (2000 skellies discovered in an unknown tomb) 9pm
...and there've been some good repeats over on the Yesterday channel, Freeview19 recently - A History of Celtic Britain, for one. Always a good idea to scan the schedules a day or two in advance.