In the heart of a huge Mughal-style garden, on the right side of the Yamuna River, in the Agra District stands the imposing Taj Mahal. Built under the order of the Mughal emperor Shah Jahan in memory of his beloved Mumtaz Mahal. Begun in 1632, the monument was completed 16 years later, in 1648. Considered the greatest architectural jewel of Indo-Islamic art, its beauty is based on a combination of full and empty spaces, concave and convex elements, the play of light and shadow and arches and domes that enhance the aesthetics of the mausoleum. The green, reddish and blue color schemes highlight the changing tones and shades of the Taj Mahal throughout the seasons. The marble sculptures with precious and semi-precious stones give the building an incredible originality. The most imposing element of the monument remains the main gate. Standing proudly in the center of the south wall of the forecourt, it is flanked by double arcaded galleries.