A Wildebeest Migration safari tour involves witnessing over a million wildebeest and zebras migrating between the Serengeti in Tanzania and the Maasai Mara in Kenya for fresh pastures, with the peak period in Kenya being July to October for river crossings and greener grasslands. Tours typically depart from Nairobi, and can be booked through various safari operators, with prices varying by season, duration, and accommodation.