That reminded me of Ngorongoro Crater in Tanzania, which I visited in 2013 (after climbing Kilimanjaro)
Ngorongoro Crater is the world’s largest intact and unfilled volcanic caldera (a collapsed volcano), and is indeed the flagship tourism attraction of the Ngorongoro Conservation Area.
Measuring an area of 260 square kilometres (100 square miles) and extending about 20km (12.5 miles) in diameter, the crater is actually a huge caldera of a volcano that collapsed to a depth of 610m (2,000 ft) about three million years ago. Over the course of time, streams of water made their way down the crater to form little ponds, and vegetation developed all over, attracting a wide range of wild animals. The crater is host to over 25,000 animals including populations of large mammals such as elephants, buffaloes, elands, wildebeests, zebras, gazelles, hippos, and rhinos, as well as such carnivores as lions, hyenas, jackals, and cheetahs. The ponds, or rather small lakes on the floor of the crater also host a wide-range of water birds including flamingoes and pelicans. Away from the crater floor, the forests on the crater rim is home to leopards, reedbuck, warthogs, and forest birds to complete a natural zoo, and Africa’s ultimate destination to see the “Big Five” (lion, elephant, rhino, leopard and buffalo).
Source: https://www.ncaa.go.tz/pages/craters#:~:text=Ngorongoro Crater
It is part of the Serengeti, which extends northwards all the way into into Kenya, and along which thousands of wildebeests, zebras, and other ungulate animals migrate both ways throughout the year. The full trip is 800 km (500 mi). Annually, around 250,000 wildebeest and 30,000 plains zebras die usually due to predation, exhaustion, thirst, or disease. On the journey they will have to pass the Grumeti and Mara rivers though, and 3,000 crocodiles that wait and suddenly lunge at them. For every one wildebeest captured by the crocodiles, 50 drown. It is a reason why the Serengeti is so famous.
Source: https://en.wikipedia.org/wiki/Serengeti_National_Park#Great_migration