How about a quiet(-ish) day messing about on the river? Canoes are available for hire by the day. The mighty Kunene River is one of the youngest in Africa and flows more swiftly than most.
Relax with a drink and watch the sunset from a boat on the river while taking in the beautiful scenery and bird life.
For the more adventurous at heart, a Half-Day Rafting Adventure - Ondorusu Gorge