The four hills have names in the local Ju|'hoansi language: Male, Female, Child and the unnamed fourth hill. The San people consider the hills a sacred and spiritual place. For thousands of years they climbed the rocky slopes to paint animals, people and shapes that told stories about their lives and beliefs.
The paintings show animals like eland antelopes, rhinoceros, penguins, and even whales - animals that would never normally be found in the Kalahari. This tells us that the artists had seen or heard about the ocean, even though it is hundreds of kilometres away. Some paintings are believed to be more than 24,000 years old, making them older than the pyramids of Egypt.
The paintings were made using natural materials - red and orange from ochre (a kind of clay), white from chalk, and black from charcoal or manganese. Artists mixed the pigment with animal fat or egg white to make it stick to the rock. Remarkably, many of the images are still vivid today.
Tsodilo was named a UNESCO World Heritage Site in 2001. Local communities still visit to pray and leave offerings, keeping the hills as a living place of meaning rather than just a museum. Visitors are asked to be respectful and quiet, walking carefully on the rocky paths.