Personal highlights

1. Olkaria: geothermally active region in the Great Rift Valley and home of the Hell's Gate
2. Spa Resort: small spa resort with natural pools just next to the geothermal power plant
3. Geothermal: home of the largest geothermal power plants in Kenya, maybe even Africa
4. Sulfur water: swimming in a naturally hot and slimy water that smells like rotten eggs
5. Group dynamic: fun, but engaged battles in the water between two rivaling tour groups

Image sources

1. Swimming in sulfur
2. Enjoying the park
3. Fresh hot water
4. Cheeky monkeys
5. Happy tour group