Final answer:
Machu Picchu is believed to have been used for religious and ceremonial purposes by the Inca civilization. It is considered a spiritual and ancestral center with no conclusive evidence to support other theories.
Step-by-step explanation:
Historians believe that Machu Picchu was most likely used as a sacred site for religious and ceremonial purposes. Its location high in the Andes Mountains and its intricate design suggest that it held great importance to the Inca civilization. While there is no consensus among historians, it is commonly believed that Machu Picchu served as a spiritual and ancestral center, where rituals and offerings were made to the gods.
Although there is evidence of agricultural terraces and storage buildings, the lack of infrastructure commonly associated with a marketplace or school suggests that these were not the primary functions of Machu Picchu.
There is no conclusive evidence to support the idea that Machu Picchu served as an astronomical observatory or a sacrificial altar.
Learn more about Machu Picchu's purpose and significance