This one-day field trip is organized by the Arabian Plate Geology group at KAUST for ANPERC to visit the central part of Harrat Rahat that shows distinctive features of the physical volcanology of basaltic eruptions. These features include lava layers in paleo valleys, pahoehoe lava flows, a’a’ lava flows, small lava tubes, lava jointing, scoria cones, spatter cones. There are the products of the 1256 A.D. / 654 A.H. eruption, the latest eruption on Harrat Rahat.