The Taj Mahal at Agra symbolizes the technical and the aesthetic perfection of the Indo Islamic art of building. In fact, it is a product of more than a century of experience in the field of architecture and the careful thought developed within the disciplined aesthetic ideals of its author, Shah Jahan.
The spirit of perfection here is visible not only in the structural scheme but also in the selection and utilization of building materials, the technique of construction and the execution of details. The structural personality of the Taj Mahal is expressed in the form of a vast oblong with high walls and diverse compositional units within simulating a self contained fortification and reflecting imperial spirit and grandeur.
The Taj Mahal is a square-shaped structure with cut off corners resting on a drum and crowned by a double, slightly pear shaped dome. In its very conception it combines simple, pure forms with extreme geometric rigor and awe inspiring majesty. The verticality of the edifice is tempered by four small kiosks, adorned by engrailed arches the ring in the dome. They rise gracefully above the cubic mass of the mausoleum which is decorated on all four sides by wide iwan with their calligraphic bands. It is not the outer structure alone that is clearly in the tradition architectural examples. The Taj Mahal is based on the form known as “8 Paradises” (Hasht Behisht) in which chambers enclose a larger central chamber. Actually the Taj Mahal contains 16 chambers, 8 each on 2 floors surrounded by octagonal burial chamber in the center. In this funeral chamber are the Cenotaphs of Mumtaz Mahal and Shah Jahan with beautiful decorations and passages from the Quarn inlaid in the marbel.
This structure can be better understood in the light of the overall planning of the complex, which comprises of 3 principal divisions. Beginning with its Northern part, these consists of the Taj proper, the Mosque , The Guest house (Mihman Khana) and the other edifices around the ornate fourfold Garden (Chahar Bagh); and the Southern part, known earlier as Mumtazabad (now called Taj Ganj), with its cruciform roads, gates and the four Inns( Sarais), each containing a central court.
What is notable in the design of the complex, despite of its organic unity, is the hierarchical treatment of the 3 divisions; the most significant (Taj proper, garden), the less significant (Gate and forecut) and the least significant (Mumtazabad). This disposal of the structural components appears to reflect the Mughal imperial organization, with graded units superimposed on a grand sepulchral construction and demarcated areas of royalty guards and attendants and commoners as seen in the 3 division just described.