Jantar Mantar in Jaipur is the largest and best-preserved of the five astronomical observatories built by Maharaja Sawai Jai Singh II across India, and a UNESCO World Heritage Site since 2010.
History
Built between 1727 and 1734, this Jaipur observatory was the largest of Jai Singh's five Jantar Mantars (the others include Delhi, which is smaller). Jai Singh was an avid astronomer as well as a ruler, and designed these instruments to track celestial movements with remarkable precision using only geometry, without telescopes.
What to See
The Samrat Yantra here is the largest stone sundial in the world, capable of telling time accurate to about two seconds. Other instruments measure the position of stars, predict eclipses, and track the zodiac — each with a specific astronomical function that a guide can help decode.
Entry Fees
A nominal ticketed entry applies, with differential pricing for Indian and foreign visitors.
Best Time to Visit
Midday, when the sun is high enough to cast clear, readable shadows on the instruments — a guide or audio tour adds considerable value here.
How to Reach
Jantar Mantar is adjacent to the City Palace in old Jaipur, an easy walk from Hawa Mahal.
