Greenwich Park, organised by Cambridge Harriers.

The race is held in the picturesque and historic surroundings of Greenwich Park. Starting in the middle of the park by the Royal Observatory, the race takes in the wonderful panorama of the Thames and London, crossing the Greenwich Meridian, before dipping down to the bottom of the park by the boating pond and climbing the long hill up to the observatory for a second lap.

 http://www.cambridgeharriers.org.uk/meridian-10k-2k/4532315690