This is what you're here for: the mighty Victoria Falls! It's a part of the Mosi-oa-Tunya National Park, located 11km outside town before the Zambia border crossing. From the centre, a network of paths leads through thick vegetation to various viewpoints.
For close-up views of the Eastern Cataract, nothing beats the hair-raising (and hair-wetting) walk across the footbridge, through swirling clouds of mist, to a sheer buttress called the Knife Edge.
If the water is low, or the wind is favourable, you’ll be treated to a magnificent view of the falls as well as the yawning abyss below. Otherwise, your vision (and your clothes) will be drenched by spray. Then you can walk down a steep track to the banks of the great Zambezi to see the huge whirlpool called the Boiling Pot. Watch out for cheeky baboons.
Note during the dry season (from August to January) the water flow can be low to non-existent, in which case it's recommended that you cross over to the Zimbabwe side for a look at the main falls; visas are available at the border.
When there's a full moon (and just before and after) the park is open in the evenings in order to see the amazing lunar rainbow.