Inca

The Inca civilization was an ancient civilization from South America on Earth. They, like many other civilizations, were inspired by the Exxilons. (NA: The Left-Handed Hummingbird)

David Kershaw was an expert on the Incans. When his museum was doing poorly, he studied footage from the opening of the Tomb of the Bear from 1934. Watching the footage, the Doctor was able to teleport from the past into the present, taking with him the Great Bear, a valuable artefact. (WC: Vampire Hurricane)

In the Doctor's TARDIS there was an Incan quipu. (NA: Sanctuary)