Jantar Mantar, New Delhi

Jantar Mantar in New Delhi is an 18th-century astronomical observatory constructed by Maharaja Sawai Jai Singh II in 1724 to measure time, predict eclipses and track planetary motions. It contains a set of large-scale masonry and stone instruments designed for naked-eye observations.

Key instruments include the large triangular sundial known as the Samrat Yantra, the Jai Prakash hemispherical instruments and the circular Ram Yantra for altitude and azimuth measurements. The instruments are arranged for practical observation and calibration rather than decorative display.

Jai Singh II commissioned a series of such observatories in the early 18th century; the Delhi Jantar Mantar is one of several that survive and reflect early modern Indian interest in precise astronomical measurement. The instruments have been restored and are used for educational visits.

The observatory stands near Connaught Place in central New Delhi and is easily reached from central city transport hubs.

• Instruments and scale: Built as part of a network of observatories in the 18th century, many of the instruments are oversized stone devices that can be read by eye to estimate astronomical positions.
• Visit length: The site is compact and close to central New Delhi; a single visit of 30-60 minutes covers the principal instruments and inscriptions.

What to See #

• Samrat Yantra: A large triangular sundial called the Samrat Yantra, used to estimate local time and solar declination with a steep triangular gnomon and broad shadowed faces.
• Jai Prakash and Rama Yantra: The Jai Prakash and Rama Yantra instruments that allow observers to map celestial positions and measure altitudes and azimuths; these are carved into the ground and stone structures.