One of the most important historic features of the city of Agra is the gardens that line the banks of the Yamuna River. Sanctuaries of respite from the city’s heat and sites of veneration to honor the deceased, the gardens were created over a period of more than 100 years. The Taj Mahal, across the Yamuna River from the gardens, is thus part of a larger cultural context that represents an important example of Mughal landscape traditions.
The Taj Mahal was commissioned in 1632 by the Mughal emperor, Shah Jahan (reigned 1628–1658), to house the tomb of his favourite wife, Mumtaz Mahal. The tomb is the centrepiece of a 17-hectare (42-acre) complex, which includes a mosque and a guest house, and is set in formal gardens bounded on three sides by a crenellated wall. The main domed mausoleum, minarets, gardens, pavilions, gateway and other buildings are together recognized as “one of the universally admired masterpieces of the world’s heritage,” according to UNESCO.
Most Mughal charbaghs are rectangular with a tomb or pavilion in the centre. The Taj Mahal garden is unusual in that the main element, the tomb, is located at the end of the garden. With the discovery of Mahtab Bagh or “Moonlight Garden” on the other side of the Yamuna, the interpretation of the Archaeological Survey of India is that the Yamuna River itself was incorporated into the garden’s design and was meant to be seen as one of the rivers of Paradise.
The garden (bagh-i firdaus-a’in) of the Taj complex is laid out as a cross-axial chahar bagh: a large square divided into four equal quadrants by two large primary intersecting walkways (khiyaban). Each of these quadrants is further divided into four sections by smaller secondary intersecting walkways. The primary cross-axial walkways all terminate at an outer peripheral walkway that frames the garden as a whole. A shallow water canal (nahr) runs along the centre of the primary walkways; a line of equidistant water fountains runs down the center of the nahr. Geometric patterns in red sandstone depicting regular and elongated stars decorate the edges of the central pathways running on each side of the nahr.
At the intersection of the primary walkways is a raised platform with a square water tank (hauz) at its center. The raised marble water tank is called al Hawd al-Kawthar in reference to the “Tank of Abundance” promised to Muhammad.
Five fountains are located within the tank, one at each of its four corners and one in its center. The four corners of the tank have floral edged designs. Four marble benches, all placed at right angles to one another on each side of the square tank, were added to the platform by Lord Curzon in 1907-8.
The east-west walkways terminate in two-story pavilions (naubat khanas) that merge into the outer garden walls. These outer garden walls are further articulated by a blind arcade that runs along their entire lengths. Aqueducts supplied water to the garden from the Yamuna river just north of the mausoleum. The central fountains operated with an underground system of copper vessels connected by copper pipes. Travelers’ photographs from the 1860s confirm an abundance of plant varieties in the garden; however, at present the garden contains relatively few trees, consisting mainly of fairly maintained grass lawns.
Source
https://en.wikipedia.org/wiki/Taj_Mahal#Garden
https://www.wmf.org/project/mughal-gardens-agra
https://archnet.org/sites/1559
http://garden-home.org/garden-layout/taj-mahal-garden-layout.html
http://famouswonders.com/taj-mahal-garden/
http://old.world-mysteries.com/mpl_TajMahal.htm
http://www.taj-mahal.net/newtaj/textMM/GardensParadise.html
https://www.airpano.com/360Degree-VirtualTour.php?3D=Taj-Mahal-India
http://www.culturalindia.net/monuments/taj-mahal.html