Jantar Mantar

Jantar Mantar is an extraordinary open-air astronomical observatory in the heart of Jaipur — a collection of nineteen monumental stone instruments that measure time, track the heavens and predict eclipses with remarkable accuracy. Both a scientific marvel and a striking piece of sculpture, it is a UNESCO World Heritage Site and unlike anything else the city offers.

History

The observatory was completed in 1734 by Maharaja Sawai Jai Singh II, a ruler as passionate about astronomy as he was about architecture. It is the largest and best preserved of five such observatories he built across northern India. In 2010 it was inscribed on the UNESCO World Heritage list as "an expression of the astronomical skills and cosmological concepts of the court of a scholarly prince".

The instruments

Each instrument, or yantra, is built to a precise geometric design. The towering Vrihat Samrat Yantra is the world's largest stone sundial, standing around 27 metres high; its giant gnomon casts a shadow that moves visibly — as much as a millimetre or more each second — and tells local time to an accuracy of about two seconds. The Jai Prakash Yantra consists of hollowed hemispheres marked with the coordinates of the sky, while the twelve instruments of the Rashivalaya Yantra correspond to the signs of the zodiac and are still consulted by astrologers.

What to see

Walking among the instruments, it is easy to appreciate them purely as bold abstract forms in stone and marble. To understand how they actually work, however, a guide is invaluable — the demonstrations of how each device measures altitude, declination or the passage of the sun are genuinely fascinating for visitors of all ages.

Visiting tips

Visit on a clear, sunny day, when the instruments perform as intended and the shadows are sharp. Mornings are cooler and the light is excellent for photography. There is little shade, so carry water and sun protection. Jantar Mantar sits directly beside the City Palace and a short walk from Hawa Mahal, making the three easy to combine.