In the 17th century text, Girvana-padamanjari, this ghat is eulogised on the name of Someshvara Ghat. In 1586 king Raja Savai Man Singh (of Amber, Rajasthan) built his palace and developed this ghat, that is how the name given to this ghat. The ghat is primarily known for the magnificent building with exquisite, ornately carved window carvings. The porches and windows of the palace are excellent example of medieval period Rajput and Durg styles One can reach the Man Singh palace (dated ca 1600) from a narrow lane leading from a fork in the main road close to the Dashashvamedha Ghat. Alternatively, one can come to Dashashvamedha Ghat and walk down stream to the next ghat. On the top roof Savai Jai Singh-II (1686-1743) built a Hindu Observatory in 1710. Savai Jai Singh, the king of Amber estate in Rajasthan was a genius of a most unusual kind, an expert mathematician and astronomer as well as an enlightened ruler and builder. He was commissioned by Muhammad Shah, the Mughal emperor to reform the calendar, a sensitive task in the land of astrologers and with a lunar year entirely structured round the Hindu pantheon. To accomplish this at a high technical level, Jai Singh embarked on an ambitious scheme to build five observatories on a monumental scale unprecedented at that time. The astronomer-king had built such observatories (1718-1734) at Jaipur, Delhi, Mathura, Varanasi and Ujjain. They are thus the last constructions of the ‘Astronomical Stone Age’.
Based on accurate methods of construction, computation and observation of the places of fixed stars and planets with reference to motions and aberrations, the king developed the instruments. The giant stone instruments were used to study the movement of the sun, the moon, the stars and other heavenly bodies. At the entrance one meet the Bhitti Yantra (Mural Quadrant), which consists of a wall, 3.353m high, and 2.775m broad, in the place of meridian; now it is in ruins. The biggest instrument is the Samrata Yantra (King of instruments), whose wall is 10.973m in length and 1.372m in breadth and set in the plane of a meridian. One extremity is 1.937m high, and the other 6.795m, sloping gradually upwards so as to point directly to the North Pole. This helps to measure the meridian, and the declination of any planet or star, and the sun, and also the right ascension of a star, may be known. There is a smaller version of this instrument, Laghu Samrata Yantra. Another gigantic instrument, called Digansha Yantra, was used to find the degrees of azimuth of a planet or star. One can check the time on oner watch with the help of solar shadow clock; remember that this would be the local time showing about five/seven minutes difference.
7. History and development (also under Col. 5): The closely shrines at the upper part of the ghat are Someshvara, Dalabheshvara (25º 18.496’ North and 83º 00.635’ East), Rameshvara and Sthuladanta Vinayaka, which are described in the various pilgrimage journeys. Dalabheshvara (“giver of lentil”) eulogised as ‘giver of food’, is in a chamber below 2.5m from the nearby area. In the inner sanctum there is ‘stone slab figure’ (Varanasi shilapatta citra), dated c 11-12th century showing a series of miniature figures of Brahmanical divinities arranged in horizontal bands. Of course, this is dilapidated badly, however it is comparable to similar Varanasi shilapattas kept in Gwalior, Jhansi and Lucknow museums. The figures engraved there refers to main Shiva lingas, notable Keshavas (Vishnu), five Vinayakas, Adityas and Shiva’s attendants. It is remarked by Joshi (1989: p. 156) that the object of veneration to these shilapattas had assumed form of a stone slab depicting the personified City Goddess Varanasi, the river Ganga, Shiva and several deities or group of deities associated with Varanasi.
The palace and the observatory instruments on the roof are today under the threat of decay, despite the fact that the monument has been declared to be of national importance under the Ancient Monuments and Archaeological Sites and Remains Act, 1958. Most of the copper plates marking angles on the circumference of the instruments have also fallen apart, and many of them have already lost their portions. The first repairing and renovation were made in 1850s. A marble plaque affixed to a wall mentions that the observatory was restored in CE 1911-12 by the order of King Savai Madho Singh of Jaipur, under the direction of state astronomer Govindracandra Bhavan and the engineer C. E. Estaworth. . Since that time, no proper renovation and conservation work has been done.
The Observatory is protected under Ancient Monuments and Archaeological Sites and Remains Act, 1958, and managed by the ASI. Since 1987 at different phases and at different scale renovation and preservations were performed. In the year 2000 by a grant of Rs one million Department of Tourism, U.P. has renovated and repaired this historical building to an extent. But this phase of renovation is insufficient and the work is not satisfactory. In 1988 the Irrigation Department of Uttar Pradesh has re-built and repaired the ghat.