The four free-standing minarets at the corners of the platform added a hitherto unknown dimension to the Mughal architecture. The four minarets provide not only a kind of spatial reference to the monument but also give a three dimensional effect to the edifice.
The most impressive in the Taj Mahal complex next to the tomb, is the main gate which stands majestically in the centre of the southern wall of the forecourt. The gate is flanked on the north front by double arcade galleries. The garden in front of the galleries is subdivided into four quarters by two main walk-ways and each quarters in turn subdivided by the narrower cross-axial walkways, on the Timurid-Persian scheme of the walled in garden. The enclosure walls on the east and west have a pavilion at the centre.
The Taj Mahal is a perfect symmetrical planned building, with an emphasis of bilateral symmetry along a central axis on which the main features are placed. The building material used is brick-in-lime mortar veneered with red sandstone and marble and inlay work of precious/semi precious stones. The mosque and the guest house in the Taj Mahal complex are built of red sandstone in contrast to the marble tomb in the centre. Both the buildings have a large platform over the terrace at their front. Both the mosque and the guest house are the identical structures. They have an oblong massive prayer hall consist of three vaulted bays arranged in a row with central dominant portal. The frame of the portal arches and the spandrels are veneered in white marble. The spandrels are filled with flowery arabesques of stone intarsia and the arches bordered with rope molding.