Botha arrived at the coastal German colonial town of Swakopmund, on 11 February to take direct command on the northern contingent, and continued to build up his invasion force at Walfish Bay (or Walvis Bay)—a South African enclave about halfway along the coast of German South West Africa (see the map). By March he was ready to invade. Advancing from Swakopmund along the Swakop valley with its railway line, his forces took Otjimbingwe, Karibib, Friedrichsfelde, Wilhelmsthal and Okahandja and entered the capital Windhuk on 5 May 1915.