|Jantar Mantar -
Jantar Mantar is the biggest of five astronomical observatory build by Maharaja Jai Singh during the period 1727-1734 in north India. It is located very close to the City Palace. The observatory consists of fourteen
major geometric devices (or yantra in Hindi) for measuring time, predicting eclipses, tracking stars in their orbits, ascertaining the declinations of planets, and determining the celestial altitudes etc. Unfortunately no text is made available to tourists regarding the various yantras nor are there any
plaques/boards in front of them. In most of the cases local guides are not of any help either.