Tanzania's oldest and most popular national park and a World Heritage site, the Serengeti is best known for the annual migration of hundreds of thousands of wildebeest, zebra and Thomson's gazelle. Spectacular game-viewing—of buffalo, elephant, giraffe, topi, impala, Grant's gazelle, lion and leopard—is also possible here. Luxury travel specialist Jack Ezon recommends the "amazing acadia trees" at Serengeti, where visitors are treated with some of the most mesmerizing sunsets in the world.