The Comrades is a South African Ultrarun between Pietermaritzburg and Durban. It is run in alternative directions, this year being a "down" run finishing in Durban (though in truth it undulates in both directions). The approximate length is 89km and there is a strict 12 hour cutoff - participants are physically prevented from reaching the finish line when the limit is up. It attracts something like 25,000 runners each year.

The BA Club Athletic section had two runners on Sunday, Chris and Jain. They ran separately, but finished together, as they did last year.
http://www.barunner.org.uk