Koldewey Island (Russian: oстров Кольдевея, ostrov Kol'deveya) is an island in Franz Josef Land, Russia. It is 3.7 kilometres (2.3 mi) in length, highest point is 66 metres (217 ft) (temporarily named as Mountain of Carl-Christian). On the top there is a double peak stack 6 metres (20 ft) high. The second-highest point Mountain of Robert-Johann in the southwest is named after Carl Koldewey's son Robert Koldewey.