The Janta Manta Observatory in Jaipur, India, is the most important, comprehensive, and well preserved ancient observatory in India and is a UNESCO World Heritage Site. It is composed of 19 astronomical instruments with fixed installations as the main body. These astronomical instruments are immortal works of ancient observation devices known and have their own characteristics in many ways. The Samurai dice in the observatory is the world's largest stone dice. The word Janta Manta comes from Sanskrit. Literally means "computer of calculation." The Janta Manta Observatory was built during the reign of Savaj Jay Singh II and completed in 1738. It demonstrated the Indians' cosmos and ability to explore astronomy in the late Mughal era. The observatory is a masonry structure, while astronomical instruments are made of masonry and bronze. The observatory is a typical representation of Ptolemy-style positioning astronomy. The observatory also has a 12-constellation sculpture art park.