In December 1854 AD, it was shifted to a building named the Pantheon, also known as the Public Rooms or Assembly Rooms, where the elite of the city met.

     The building was being utilised for banquets, balls and dramatic performances from the last decade of the 18th Century. The estate of the Pantheon was the property of Hall Plumer, civil servant and public works contractor who subsequently, in 1793 AD, assigned the grounds to a Committee of 24, which regulated the public amusements in the city at that time. In 1821 AD, the Committee sold the main house and central garden space to E.S. Moorat, a wealthy Armenian merchant, who in turn, sold it back to the Government in 1830 AD, for Rs.28,000. The property was originally 43 acres in extent and stretched from Casa Major Road to the present Police Commissioner’s Road, and it was flanked by the Pantheon Road and Halls Road.

     The Public Library was started in 1853 AD. It was opened to the public in June 1862 AD. The construction of the library and lecture hall began in December 1873 AD and completed in 1875 AD and formally opened by the Governor on March 16, 1876 AD. Captain Mitchell, Superintendent, was responsible for strengthening the library. He is regarded as the originator of the Connemara Public Library.

     It was formally opened on December 5, 1896 AD by Sir Arthur Elibank Havelock, the then Governor and named after its progenitor, Lord Connemara, Governor of Madras. Designed by H.Irvin, the then Consulting Architect to the Government of Madras, it had a magnificent hall with a splendid reading room and beautiful teak wood shelves.

     The library had an imposing tower 200 feet high, the highest in Madras at that time. But in March 1897 AD, the tower was demolished as it was found to be in a precarious condition.

     Libraries controlled by different bodies which were in need of space were invited to occupy some portion of the Connemara Library. The Madras Literary Society Library was the first to function inside the Connemara Library until it was shifted in 1905 AD to its present building on College Road. The Madras University Library occupied the space vacated by the Madras Literary Society Library and functioned there until 1928 AD when it moved to Chepauk. The Oriental Manuscripts Library which was also housed in the Connemara Library till 1935 AD, moved into the University Buildings at Chepauk. Books were purchased on behalf of the Victoria Technical Institute from the Dhanakoti Mudaliar Endowment and still housed in the Fine Arts Section of the Connemara Public Library. Later the library came under the control of the Director of Public Instruction.

     In 1854 AD, a young cheetah and tiger were kept in the museum and visitors came to see them from distant places. As visitors to the museum increased, Dr. Balfour requested the Nawab of the Carnatic, to send the wild animals he had to the museum. In September 1855 AD, a notification was issued asking for the animals to be gifted to the Museum Zoological Gardens. By the first half year of 1856 AD, the Madras Museum had zoological garden with 360 animals. In 1863 AD, the City Municipality took over the Zoological Gardens and shifted it to the People’s Park.

     The plans for the Madras Aquarium were drawn up in 1905-1906 AD by Dr. Thurston, the then Superintendent of the Museum in consultation with a Committee. As this was the first Aquarium, methods of aeration, etc. found useful in Europe had to be suitably modified and adopted. The aquarium was opened to the public on October 21, 1909 AD and was very popular.

     The period 1941-1946 AD were bad years for the Museum. A great part of the buildings and the grounds had to be handed over for an ARP depot stationed in the Museum. The galleries had to be used as storage rooms and therefore the showcases were removed. The most valuable among the collections, such as bronzes, copper plate grants, selected coins, relic caskets of Bhattiprolu, etc. were sent to places of safety. As the Amaravati sculptures were too heavy and difficult to transport, the Government ordered that they should be protected in situ in the Gallery.

     In December 1896 AD, the Front Building (Anthropological Galleries) and The Museum Theatre were opened. The new extension (main entrance) was built in 1939 AD in order to display stone sculptures, period-wise. The Government Museum took over the Victoria Technical Institute Building (constructed in 1909 AD) and named it as National Art Gallery and was thrown open to the public on November 27, 1951 AD.

     A separate building for Contemporary Art was opened in January 25, 1984 AD and a new Children’s Museum building was opened in April 1988 AD. The Raja Ravi Varma paintings, which are considered as National Treasures, have been placed in a gallery with Fibre Optic lighting. This system of lighting gives a dramatic lighting effect. The Contemporary Art Gallery has been lit using Dichroic Halogen lamps. These lamps reflect back the heat. They also have a pleasing visual effect. These lighting methods are technology demonstrators and a first for museums in India at the time of their installation in 2001 AD.