Honorary Mentions: The Octagon Earthworks & The Konark Sun Temple
The Octagon Earthworks, Ohio
The Octagon Earthworks is part of the engineering of the Native American Hope Culture. It dates back to 100-300 AD. The earthworks are a section of other similar archaeological structures situated in Ohio.
Researchers in the mid 1900s discovered that the Octagon Earthworks were built as a Lunar Observatory designed to track the motions of the moon. They are precisely aligned to the cycle of the moon in the night sky. The earthworks incorporate alignments to the 8 major moonrises and moonsets of the repeating 18.6 year Lunar Cycle. The northernmost point of the 18.6-year cycle of the Lunar Orbit is also observed. The moon can be seen rising directly along the axis of the earthworks!
A 19th Century plan of the Earthworks (A & B are the Octagon Earthworks)
By User: (WT-shared) 2old at wts wikivoyage [Public domain], from Wikimedia Commons
The Konark Sun Temple, India
The Konark Sun Temple in Odisha, India was constructed around 1250 AD. The temple complex is in the shape of a gigantic chariot possessing elaborately carved stone wheels, pillars and walls. The wheels of the temple function as sundials which can be used to calculate time accurately to a minute including day and night!