Lake Guinas is the lesser-known twin of Otjikoto: another dolomite sinkhole lake about 38km west of Tsumeb via the D3043 gravel road, and notably larger and deeper. While Otjikoto sits conveniently beside the tar highway, Guinas requires a deliberate detour on a rougher track, which is exactly why most visitors skip it. That is your opportunity.
The lake is roughly 300 metres long and 175 metres wide near the surface, with sheer dolomite walls dropping away into extraordinarily clear water. Its depth of 133 metres makes it one of the deepest natural lakes in Namibia. The surrounding bush is quiet and the scenery is stark — flat thorn scrub giving way abruptly to this improbable blue pool. Guinas is privately owned farmland, so check access conditions before heading out; a small entry fee may be charged. Four-wheel drive is not required in the dry season, but the road is corrugated.