This is Kokino. It may not look like much anymore, but it’s one of the oldest observatories in the world. Located in Northeastern Macedonia, Kokino is a temple. Part of an ancient culture dating back at least 3800 years. The temple contains stone markers which were clearly used to track the positions of the Sun and Moon on the Eastern horizon. Astronomy really is among the oldest of the sciences.
Kokino is listed by UNESCO as a world heritage site, and is on NASA’s list of ancient observatories.