The Jantar Mantar is located in the city of Jaipur, Rajasthan, India.

The Jantar Mantar was built by Maharaja Jai Singh II of Jaipur, Rajasthan.

The Jantar Mantar was built between 1724 and 1730.

There are a total of 19 astronomical instruments in the Jantar Mantar.

The Samrat Yantra is the largest instrument in the Jantar Mantar.

The Samrat Yantra is used for measuring the time of day, tracking the location of celestial bodies, and making astronomical observations.

The Jai Prakash Yantra is used for making astronomical observations.

The Rashivalaya Yantra is used for tracking the location of celestial bodies.

The Misra Yantra is used for measuring the time of day, tracking the location of celestial bodies, and making astronomical observations.

The Jantar Mantar is the only observatory in the world that was built by a single person, Maharaja Jai Singh II.

The Jantar Mantar was declared a UNESCO World Heritage Site in 2010.

The Jantar Mantar is a testament to the scientific achievements of ancient India, a unique example of astronomical architecture, and a popular tourist destination.

The Jantar Mantar receives approximately 300,000 visitors each year.

The Jantar Mantar can be visited all year round, but the best time to visit is during the winter months (October to March) when the weather is pleasant.

The entry fees for the Jantar Mantar are INR 20 for Indian nationals and INR 50 for foreign nationals.