In the period corresponding to the Middle Ages of Europe, Mahometan architecture was introduced in India and many beautiful buildings were erected in a new style blending the foreign art with the native ideas and taste, but offering a marked contrast to that which preceded it. Although China was one of the oldest of civilized countries it contains but few monuments of great antiquity. The temples and palaces, being built of wood, were exposed to fire and decay, and were often pulled down and rebuilt. With the exception of the great wall and of the numerous bridges crossing rivers or arms of the sea, there are no important stone constructions to be found there. The latter are formed of huge granite piers, spanned by massive stone lintels, requiring the united labour of thousands of men to convey them from the quarries to their destination and to set them in place. In the mountains the ravines are bridged by iron chains suspended from cliff to cliff. The great wall was built as a frontier protection, and extended the entire length of the boundaries of the country. It has always been kept in repair, although obviously absurd as a fortification in modern times. It is of great thickness, and upward of twenty feet in height. The foundations are of stone, and the upper part of brick with stone facing, the joints of which are extremely accurate. At short intervals there are towers, placed so that the middle distance between any two is within arrow-shot. Chinese wooden buildings are all much alike, whether temples or palaces. As a rule, they have but one or two stories; they are surrounded by porticos, consisting of wooden columns mounted on stone bases, without capitals, which are replaced by a species of bracket. The roofs project considerably, and their angles are turned up, this form being undoubtedly borrowed from the old tent habitations, which were composed of hides stretched tightly on bamboos. The tiles with which they are covered are semicylindrical in shape and are enamelled with bright colour. The celebrated taas, or Buddhist towers, are of similar construction. They are generally octagonal, and from six to ten stories high. Each story is set back from the one below, and has a balcony and projecting roof, with bells hung in the angles. The walls are covered with tiles or paintings. A high staff is placed on the top and connected with angles of the roof by chains. The tower of Nankin, known as the Porcelain Tower, was the most famous. It was erected in 1431, and but recently destroyed. The Chinese have always excelled in artificial or landscape gardening. In this work they build airy bridges, with open-work balustrades, pavilions highly ornamented and enriched with painting and gilding, and boundary walls with circular openings, disclosing vistas of great beauty.