In the Inca Cosmology, huacas are places where the three worlds of the andean cosmos connect. They normally have under-world features such as a cave, stairs, and something going upwards. According to a new ontology to understand Inca Cosmology, these huacas were living organisms. Which may explain why they were irrigated with water, chicha, or blood @j.mckimmalville2010.
Huacas can also be places of great symbolism, such as where a lightning struck, but could also be mummies, or children born with deformities.
Huacas can be killed by enemies, and they were dressed for occasions. This also means that huacas were able to protect the inca, in pretty much the same way groups of soldiers could.