This is probably the most famous of Isfahan's bridges. It is made up of a series of 33 arches and was commissioned in 1602 by Shah Abbas I from one of his Generals. The name - Si-o-Seh Pol is derived from the Farsi for 33 (Si-o-Seh). The bridge is built on a series of pontoons of great width and there is a famous tea-house amongst them which is accessible from the southern bank.
The bridge was originally known as the Bridge of Allahverdi Khan who was the general responsible for its construction. The lower level of 33 arches is surmounted by a second layer, with one arch above each of the pontoons and two arches above the lower single arch, giving it its name and rhythmic appearance. The road along the top is sandwiched between high walls which give some shelter from the wind as well as protection for travellers who can walk along the footpaths on either side to avoid the crush of the traffic. Originally there were frescoes on the walls which Sir William Ousely, who saw them in 1823, felt to be dangerous for the morals of passers by!
The bridge itself is 295m long and 13.75m wide. The thirty four piers on which it is constructed are 3.49m thick and the arches are 5.57m wide. The southern side of the bridge, where the waters of the Zayandeh run more swiftly has supplementary arches, and it is this that makles them suitable as a tea house. The bridge acted as a springboard for the development of the Khajou Bridge some 50 years later.
In 1598, when Shah Abbas decided to move the capital of his Persian empire from the north-western city of Qazvin to the central city of Isfahan, he initiated what would become one of the greatest programmes in Persian history; the complete remaking of the city. By choosing the central city of Isfahan, fertilized by the Zāyande roud ("The life-giving river"), lying as an oasis of intense cultivation in the midst of a vast area of arid landscape, he both distanced his capital from any future assaults by the Ottomans and the Uzbeks, and at the same time gained more control over the Persian Gulf, which had recently become an important trading route for the Dutch and British East India Companies.
The Chief architect of this colossal task of urban planning was Shaykh Bahai (Baha' ad-Din al-`Amili), who focused the programme on two key features of Shah Abbas's master plan: the Chahar Bagh avenue, flanked at either side by all the prominent institutions of the city, such as the residences of all foreign dignitaries, and the Naqsh-e Jahan Square ("Examplar of the World").Prior to the Shah's ascent to power, Persia had a decentralized power-structure, in which different institutions battled for power, including both the military (the Qizilbash) and governors of the different provinces making up the empire. Shah Abbas wanted to undermine this political structure, and the recreation of Isfahan, as a Grand capital of Persia, was an important step in centralizing the power.The ingenuity of the square, or Maidān, was that, by building it, Shah Abbas would gather the three main components of power in Persia in his own backyard; the power of the clergy, represented by the Masjed-e Shah, the power of the merchants, represented by the Imperial Bazaar, and of course, the power of the Shah himself, residing in the Ali Qapu Palace.