McMahon Islands are two low, peaked, rocky islands, 0.5 miles (0.8 km) north of the Thala Hills, Enderby Land. The islands, about 60 m (197 ft) above sea level, are separated by a narrow channel. Plotted from Australian National Antarctic Research Expeditions (ANARE) air photos taken in 1956 and visited by the Australian National Antarctic Research Expeditions (ANARE) (Thala Dan) in February, 1961. Named by ANCA for F.P.