Varanasi's Jantar Mantar is a historic observatory built under Jai Singh of Amber, one of several astronomical sites he commissioned across northern and western India. It is smaller than the better-known observatories in Delhi and Jaipur, but its masonry instruments still show the same mix of science, architecture, and royal ambition.
The observatory is part of Man Mahal, near Dashashwamedh Ghat. The complex also includes a virtual experience museum with light-and-sound displays on the Ganges, Varanasi life, and local culture.