The mainly ice-covered Prehn Peninsula (75°06′S63°30′W) is 37 kilometres (20 nmi) long and 19 kilometres (10 nmi) wide, between Hansen and Gardner Inlets, on the eastern coast and at the base of Antarctic Peninsula. First observed from aircraft by the RARE, 1947-48. Mapped by USGS from surveys and US Navy air photos, 1961-67. Named by US-ACAN for Lt. Cdr. Frederick A.