The JANTAR MANTAR monument of Jaipur, Rajasthan, India
is a collection of nineteen architectural astronomical instruments,
built by the Rajput king Sawai Jai Singh, and completed in 1738 CE.
It features the world's largest stone sundial, and is a UNESCO
World Heritage Site. The monument features masonry, stone
and brass instruments that were built using astronomy and
instrument design principles of ancient Hindu Sanskrit texts.