Why was Taj Mahal built on the banks of Yamuna River?

 Taj Mahal was built on the banks of Yamuna River because the location was chosen by the Mughal emperor Shah Jahan as the final resting place for his beloved wife, Mumtaz Mahal. 

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The emperor wanted to built a grand and beautiful monument in her memory, and the river provided a natural source of water for the construction of the building. Additionally, the river also served as a means of transportation for the materials used in the construction.

Also, Mughal emperor Shah Jahan wanted to see Taj Mahal from Agra Fort. There is palace called Mussamman Burj, from where Mughal emperor Shah Jahan spent his last years of life and used to Taj Mahal from this palace.

Taj Mahal is built on a wooden foundation, foundations represented the biggest technical challenge to be overcome by the Mughal builders. In order to support the considerable load resulting from the mausoleum, the sands of the riverbank needed to be stabilised. To this end, wells were sunk and then cased in timber and finally filled with rubble, iron and mortar — essentially acting as augured Piles.

After construction of the terrace was completed, work began simultaneously on the rest of the complex. Trees were planted almost immediately to allow them to mature as work progressed.

Since Timber, probably Mahagony, is one of the main constituents of the foundation of Taj Mahal, and the fact that an apt moisture is required to maintain the structural stability of timber, the Taj Mahal was built near Yamuna.

The water from Yamuna keeps the foundation moisturized at all times and this way the structure stands perfectly, the increase of pollutants in the river and depletion of water from Yamuna, is also one of the reasons that Taj Mahal was sinking some time ago, this was taken under consideration and large scale reconstructions were done around the foundation and measures were taken so that adequate water reaches the timber foundation.

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