Inca Sun Temple
The sun temple is the largest and best preserved surviving building from the Incan outpost of Ingapirca. It is unique in that it is the only oval building in the Incan empire. Its function is not certain, but may have been used for religious purposes or as a fortress. It may also have functioned as a calender, as its east-west orientation would allow the way sunlight filled the rooms to indicate the spring or fall solstices.