Mariental is a town of 10,000 inhabitants in south-central Namibia, lying on the B1 national road 232 kilometres (144 mi) north of Keetmanshoop and 274 kilometres (170 mi) southeast of Windhoek. It lies at an elevation of 1,090 metres (3,580 ft). Mariental is connected to the TransNamib railway line from Windhoek to Keetmanshoop. The town and the surrounding area are situated in a hot, arid region.

The B1 is a national highway of Namibia, and is the country's longest and most significant road, running the length of the country from south to north. It connects Noordoewer in the south on the South African border with Oshikango in the north on the Angolan border via Namibia's capital city Windhoek.