Mariental lies 260 kilometres south of Windhoek on the B1. The little town provides for the surrounding farms and Nama communities. With the construction of the Hardap Dam in 1962, irrigation farming on a considerable scale was introduced to the area causing an upswing for the town of Mariental. Nowadays, mainly melons, lucerne, wine and maize are being cultivated below the dam.
The Hardap Dam is the biggest of its kind in Namibia with a water surface area of about 25 sqkms and an 862 metre long dam wall. It dams up the waters of the Fish River, the only river in the country's interior that flows just about all year round, although carrying very low quantities of water during the dry season.