Fodor's Expert Review Jantar Mantar
This odd grouping of what might seem like random modern sculptures is actually a huge sundial and open-air observatory. One of five such installations built by the Maharaja Sawai Jai Singh II of Jaipur in the early 18th century (the one in Jaipur is the best preserved), it's an interesting place to wander, though better understood with a good guide. The Samrat Jantar, the sundial, is the largest structure here, at 90 feet. The Hindu Chhatri, a small domed building, can tell when the monsoons are coming in and whether the weather will change. The Jai Prakash shows the sun's position at the time of the equinox. The Ram Yantra consists of two large buildings, both with open tops: they're used, together, to measure the altitude of stars. The Mishra Yantra consists of five instruments, which are used to measure the shortest and longest days of the year.