Which airport should you fly into?
Your arrival airport is the single biggest constraint on a South Africa trip. It decides which coast you're on, which safari is reachable, and whether your route has to backtrack. Pick it before you pick anything else.
Cape Town (CPT)
The country's most scenic arrival: you fly in over the mountain and land twenty minutes from the city centre. Smaller, calmer, and easier than Johannesburg.
Best for: a Cape-first trip. Cape Town, the Winelands, the Whale Coast, and the Garden Route all open up from here. Most first-timers should start at CPT.
Johannesburg (JNB)
O R Tambo is the country's main international hub. More flights, more airlines, and the only sensible connection point for Kruger, the Panorama Route, and anywhere north or east. Not a destination in itself for most travellers, but worth one night for the Apartheid Museum if your schedule allows.
Best for: a safari-first trip, or anything anchored on Kruger and the interior.
Durban (DUR)
Underrated, warm, and the right entry if your trip is KwaZulu-Natal only. The gateway to the KZN coast, iSimangaliso Wetland Park, Hluhluwe-iMfolozi, and the southern Drakensberg.
Best for: a KZN-only trip. A lot of people fly into Cape Town and drive across the whole country to get here. Don't. Fly into Durban.
Multi-city: the structure most two-week trips should use
Fly into Cape Town and out of Johannesburg, or vice versa. It buys you the Garden Route in one direction and Kruger in the other, with no backtracking. The open-jaw ticket is usually the same price as a return and saves you a domestic flight and a wasted day.
If your trip is Cape Town plus safari, this is the structure: into CPT, a week in the Cape, fly to the Kruger gateway (Nelspruit, Hoedspruit, or Skukuza), two or three nights on safari, out of JNB with one Joburg night for the museum on the way.
The one mistake
Flying into Johannesburg and driving to Cape Town, or vice versa, "to see the country." It's fourteen to sixteen hours of flat interior that isn't the point of your trip. Fly it.