The massive Taj Gateway was completed in the year 1648 and stands 30 m high. The gateway is topped by small cupolas or chhatris. From a distance the Taj Mahal looks like a miniature on the landscape, which appears to grow as you approach it. 
However, as you enter the open square before the main entrance to the Taj Mahal, you will be surprised to find the Taj disappear from your sight. From within this square the Taj is hidden by a massive red sandstone gateway. Symbolic of the divide between the material and the spiritual, the gateway is decorated in calligraphy with verses from holy Koran. The original door of the gateway was made out of the solid silver and there are letters inscribed on it from top to bottom. All the letters appear to be of same size to the naked eyes. Actually, the engravers enlarged and stretched the lettering as their distance from the ground increased, creating an illusion of uniformity to the naked eyes.

The actual function of this magnificent gateway was to prevent people from getting any glimpse of the tomb inside until they are right in the doorway itself. The tomb is visible from here only and the view stuns the eyes as one walks forward. The dwarfing images of people moving around the tomb 70 m high are excellent and the best that you can get.

The Taj Mahal incorporates and expands on many design traditions, particularly Islamic, Persian, Hindu and earlier Mughal architecture.
The overall design derived inspiration from a number of successful Timurid and Mughal buildings: these include the Gur-e Amir, Humayun's Tomb, Itmad-Ud-Daulah's Tomb (sometimes called the Baby Taj), and his own Jama Masjid. Under Shah Jahan's patronage, Mughal building reached new levels of refinement:, previous Mughal building had primarily been constructed of red sandstone; Shah Jahan promoted the use of white marble inlaid with semi-precious stones.

On the inner (garden) side, the wall is fronted by columned arcades, a feature typical of Hindu temples later incorporated into Mughal mosques. The wall is interspersed with domed kiosks (chattris), and small buildings which may have been viewing areas or watch towers (such as the so-called Music House, now used as a museum).