Tourists are arriving at the Maasai Mara national park ahead of the widely anticipated annual wildebeest migration. air travel industry players are also angling to tap into the numbers of travellers heading to the Mara from Nairobi. about 1.5 million wildebeest cross the Mara river from Tanzania's Serengeti national park into Kenya's Maasai Mara, in a spectacular July to September event also known as the eighth wonder of the world.