[2] Its highest point is 66 metres (217 ft) (temporarily named as Mountain of Carl-Christian[citation needed]).

The island belongs to the Russkaya Arktika National Park since 15 June 2009[citation needed].

There is the same arctic climate and flora as the "mother" island Salm but Koldewey is fully unglacierized.

The island extends in two directions: in the north more dynamically with a longish steep cape and small islet Schoenau at the end, in the southwest very shallow, long flat bar cape with over 6 km (4 mi) underwater reef not deeper as 35 metres (115 ft), that connects with the glacierized side of the Salm Island.

The middle peak of the large bank (temporarily named Siegfried-Elof Bar) reaches just a meter and a half under the surface and lies in the Lavrov Sound 12 km (7 mi) opposite to the famous Cape Tegethoff on Hall Island.