3 Days Tanzania Safari from Zanzibar. Ngorongoro Crater and Serengeti National Park. Serengeti is one of the planet’s oldest and most scientifically significant ecosystems. With Ngorongoro Crater—the world’s most enormous unbroken caldera—magnificent Serengeti National Park makes a perfect safari holiday. Standing close to each other on the map makes it very easy to combine these two famous spots for safari.