The Transkei is one of the wildest and most beautiful stretches of South African coast, running roughly from East London in the south to the KwaZulu-Natal border in the north. This is the Wild Coast — cliffs of black rock, long empty beaches of golden sand, subtropical forest running down to the surf, and hundreds of round Xhosa rondavels dotting the green hills inland. Under apartheid it was a "homeland" notionally independent of South Africa; since 1994 it has been part of the Eastern Cape, and it remains poorer and less visited than the rest of the country.
That is exactly its appeal. Backpacker lodges at Coffee Bay, Port St Johns, Cintsa and Bulungula have been welcoming independent travellers for decades and provide safe, easy bases to walk the coast, ride horses along the beach, surf, fish, or visit neighbouring Xhosa villages with a local guide. The Hole in the Wall — an enormous natural arch carved through a sea cliff by the Indian Ocean — is the best-known landmark, an hour's walk south of Coffee Bay along the rocks and strandline.
A practical note: Mthatha (formerly Umtata), the regional capital on the N2, has a poor reputation for safety and is worth passing through rather than stopping in. Drive it in daylight, keep valuables out of sight, and base yourself instead at one of the coastal lodges. The coast itself is overwhelmingly safe for visitors, and the people some of the most welcoming in the country.