Megaron 2, Phrygian pebble mosaic from Gordion, 8th century BCE (Gordion Museum, Turkey). Watercolour by Johnathan Last, 1965. This incredibly inventive (and absolutely unique) masterpiece is also the oldest known mosaic pavement in the world. Although it was dug up as recently as 1956, it's been poorly preserved and now only fragments survive. From: Frank Matero et al - 2011 - Gordion Pebble Mosaic Pavements, Interim Report, Phase 1.