Man Singh Observatory
Varanasi, India
Jantar Mantar in Varanasi is an observatory designed to be used with the naked eye. It is one of the five Jantar Mantar in India and was built in 1737 by Maharaja Jai Singh II of the Kingdom of Amber (later called Jaipur).
Observatory data from Wikidata (CC0). Summary from Wikipedia (CC BY-SA).