In the southwest of Sua Pan lies an isolated granite outcrop, some 10m high and a kilometre long, known as Kubu Island. It forms the shape of a crescent, and its slopes are terraced with fossil beaches of wave-rounded pebbles, providing startling evidence of the prehistoric lake's former water levels. Crowned with an array of ancient, gnarled baobabs and surrounded on three sides by a vast grey emptiness, Kubu has a unique atmospheric beauty.

At night, with the wind moaning through the baobabs, it is easy to imagine the waves of a great inland sea lapping at its pebble beaches. Many of the island's rocks are white, covered in ancient, fossilised guano from the water-birds that used to perch here when it was surrounded by the lake. The moonlight reflecting off the pan's white surface gives the place an almost supernatural atmosphere, which is heightened by the mystery of Kubu's former inhabitants. The shoreline is littered with Stone-Age tools and arrowheads, while concentric dry stone walls on the islands survive from a much more recent village, perhaps around AD1400–1600, and outside this are a number of stone cairns.

Archaeologists have linked these with the dynasty of Great Zimbabwe, and think that these were probably the most southwestern tip of that state. In Riddle of the Stone Walls (see Further Reading) Alec Campbell explains the theory that they could have been remote 'circumcision camps' to which the boys of the tribe were taken for circumcision and ceremonies leading to adulthood. It is suggested that perhaps ceremonies took place within the walls, and every class that 'graduated' then built a separate cairn.

Campbell also noted that the people of the nearest village, Tshwagong, hold Kubu and the nearby Thithaba Islands as sacred, and men over 16 years of age visit the islands to make contact with God, singing a particular song for rain and leaving offerings on the ground.

Note that Kubu is a national monument, and there are plans to station a warden here to ensure that visitors don't damage anything.

Getting there

From the north there are endless possible routes to Kubu Island (GPS: KUBU-I), and you can expect it to take about 3–4 hours from the main Maun–Nata road. Easiest is probably to take one of the many tracks that leave the main road between about 30km and 15km west of Nata. Follow your nose (or, more practically, your GPS) towards Thabatshukudu Village (GPS: THABAT), which is about 70–75km south, depending on the track that you take.

From there it's about 10km southwest to the Tswagong Veterinary Gate, through which any north–south traffic between Sua and Ntwetwe pans passes – so tracks will lead you there. This is about 3km north of the small village of Tshwagong (GPS: TSHWAG), from where it's about 14km in a straight line southeast to Kubu Island. (There are several tracks here, so just head southeast and follow your GPS.)

Note that the track that leaves Gweta in a south then southeasterly direction, ending at the Tswagong Veterinary Gate, passes over several long stretches of Ntwetwe Pan, and so is dangerously muddy during the earlier months of the year.

From the south, it's best to start by heading for the village of Mmatshumo (GPS: MMATSH). Again you'll find a number of tracks from the Orapa-Francistown road which will lead you here; the shortest leaves the main road around (GPS:TURNM1). From there it's about 23km to Mmatshumo. Heading north from there, there's a good view of the pan to your right after about 5km, before the track bends west and back north to cross the small Tsitane Pan, crossing the veterinary fence at (GPS:TSIVET). Then a straight track heading north by northeast brings you to Tshwagong (GPS: TSHWAG) after about 20km.

Note that during the dry season you can take a short cut about 7km north of the vet fence, at around (GPS:TURNM2), which heads east- northeast across the pan to Kubu; but don't try this when the pans are wet!