A marble portal of the Taj Mahal, Agra, India.	Taj Mahal at dusk, on the southern bank of the Yamuna (Jumna) River, Agra, India.

The sandstone gateway at the southern end of the Taj Mahal complex, Agra, India also spelled TADJ MAHALL, mausoleum complex in Agra, northern India, on the southern bank of the Yamuna (Jumna) River. In its harmonious proportions and its fluid incorporation of decorative elements, the Taj Mahal is distinguished as the finest example of Mughal architecture, a blending of Indian, Persian, and Islamic styles.

It was built by the Mughal emperor Shah Jahan (reigned 1628-58) to immortalize his favourite wife, Mumtaz Mahal ("Chosen One of the Palace"). She died in childbirth in 1631, after having been the emperor's inseparable companion since their marriage in 1612. The name Taj Mahal is a corruption of her title. The plans for the complex have been attributed to various architects of the period, although the chief architect was probably Ustad Ahmad Lahawri, an Indian of Persian descent. The five principal elements of the complex--main gateway, garden, mosque, jawab (literally "answer"; a building mirroring the mosque), and mausoleum (including its four minarets) — were conceived and designed as a unified entity according to the tenets of Mughal building practice, which allowed no subsequent addition or alteration. Building commenced about 1632. More than 20,000 workers were employed from India, Persia, the Ottoman Empire, and Europe to complete the mausoleum itself by about 1638-39; the adjunct buildings were finished by 1643, and decoration work continued until at least 1647. Construction of the 42-acre (17-hectare) complex spanned 22 years at a cost between four and five million rupees.

Resting in the middle of a wide plinth 23 feet (7 metres) high, the mausoleum proper is of white marble that reflects various hues according to the intensity of sunlight or moonlight. It has four nearly identical facades, each with a wide central arch rising to 108 feet (33 metres) and chamfered (slanted) corners incorporating smaller arches. The majestic central dome, which reaches a height of 240 feet (73 metres) at the tip of its finial, is surrounded by four lesser domes.

The garden is set out along classical Mughal lines — a square quartered by long water courses (pools) — with walking paths, fountains, and ornamental trees. Enclosed by the walls and structures of the complex, it provides a striking approach to the mausoleum, which can be seen reflected in the garden's central pools.

The southern end of the complex is graced by a wide red sandstone gateway with a recessed central arch two stories high. White marble paneling around the arch is inlaid with black Qu'ranic lettering and floral designs. The main arch is framed to either side by two pairs of smaller arches. Crowning the northern and southern facades of the gateway are matching rows of white cupola-like chattris (chhattris), 11 to each side, accompanied by thin ornamental minarets that rise to some 98 feet (30 metres). At the four corners of the structure are octagonal towers capped with larger chattris.