Jantar Mantar, Delhi

Jantar Mantar, located on Janpath in Delhi, India, is an astronomical observatory built in 1724 by Maharaja Sawai Jai Singh II of Jaipur during the Mughal period. It was designed to measure time, predict eclipses, track celestial bodies, and create astronomical tables. Spread over an area of approximately 1,500 square metres, this observatory showcases a blend of Hindu architectural principles and scientific innovation. Its highlights include the Samrat Yantra (large sundial) and the Jai Prakash Yantra, large geometric instruments designed for precise astronomical calculations. Jantar Mantar is an important site for both cultural tourism and historical research, providing insight into the scientific achievements of the 18th century in India.

The Jantar Mantar in Delhi exemplifies the architectural style of large-scale geometric construction, serving a functional and scientific purpose. Built in 1724 by Maharaja Sawai Jai Singh II, it reflects a fusion of Rajput and Mughal architectural influences, with an emphasis on accuracy and durability. The observatory's design was carefully planned according to astronomical principles, using angled planes, circular structures, and a graduated scale for celestial measurements. The structure is constructed of masonry, stone, and lime plaster, demonstrating the advanced construction techniques of the time. The observatory houses several large instruments:

• Samrat Yantra – the largest sundial that accurately measures time
• Jai Prakash Yantra – a hemispherical structure for observing sky positions
• Rama Yantra – a cylindrical instrument for measuring altitude and azimuth
• Mishra Yantra – for determining the exact time of noon at different locations
• The layout includes integrated small quadrants, scales, and observational platforms

The layout and orientation of each instrument were precisely calculated to track sky phenomena, showcasing a fusion of architectural art with scientific innovation.