Jantar Mantar, Jaipur

Jantar Mantar is a collection of about twenty stone and marble instruments built by Sawai Jai Singh II between the late 1720s and 1738, next to his palace inside the walled city. Nothing here has a lens. Each device is a piece of architecture sized so that a shadow or a sightline can be read to a fine tolerance: sundials, hemispherical bowls sunk into the ground, graduated arcs, and a separate instrument for each sign of the zodiac. The largest, the Vrihat Samrat Yantra, is a stair-like gnomon tens of metres high whose shadow moves fast enough to watch. The site is on the World Heritage list and makes far more sense with a guide than without one.

History

Sawai Jai Singh, founder of Jaipur, had built several instruments by 1728, and work continued until 1738; in 1735, at its peak, at least 23 astronomers worked here, and Jaipur replaced Delhi as his main observatory until his death in 1743. Support fell away under Ishwari Singh, revived under Madho Singh I, and under Pratap Singh the site was turned into a gun factory; Ram Singh completed a restoration in 1876, inserting lead into the scale lines and replacing plaster instruments with stone, and after more neglect it was restored again in 1901 under Madho Singh II. Its 19 instruments include the world's largest stone sundial, and the observatory is a World Heritage Site (Wikipedia, Jantar Mantar, Jaipur).

What to look for

• Vrihat Samrat Yantra - the huge sundial whose shadow visibly creeps along a graduated marble arc.
• Jai Prakash Yantra - two sunken marble bowls mapping the sky, read from inside the hollows.
• The Rashivalaya - twelve separate instruments, one per zodiac sign, each set at its own angle.
• Ram Yantra - open cylindrical structures used to take altitude and azimuth readings by eye.

When to go

Late morning to early afternoon is when the instruments actually work, since most of them need direct sun; an overcast sky or a late arrival leaves half the site inert. October to March is bearable outdoors. Come at opening time if you want the yard without tour groups, and hire a guide at the gate rather than guessing.

Practical notes

The site is a bare, unshaded courtyard and the Rajasthan sun is punishing from March onwards. Without explanation the instruments read as abstract concrete, and guide quality varies a lot; some rush through memorised patter. It is small, and the ticket is priced for the combined palace circuit rather than for the hour you actually spend here.

Nearby

The City Palace is next door and Hawa Mahal is a few minutes' walk up the bazaar.

Key facts