Shah/Jame Abbasi Mosque, also known as Imam Mosque, renamed after the 1979 Islamic revolution in Iran, is a mosque in Isfahan, standing in south side of Naghsh-e Jahan Square. This Mosque has been built during the Safavid period, ordered by the first Shah Abbas of Persia. The mosque, which is also known as Jame Abbasi Mosque and Royal Mosque, was intended to replace the Jame Mosque of Isfahan as the venue for the Friday Prayers. Construction of the mosque began in 1612 in the 24th year of Shah Abbas’ reign. Iranian craftsmen invented the seven-color tile, which has a quicker and more cost-effective creation process, to use in the decoration of Imam (Shah) Mosque. It is said that 18 million bricks and 475,000 tiles were used in this mosque. The 27- meter-high entrance of the mosque, which opens to Naqsh-e Jahan Square, is bound by two 42-meter-high minarets and has multi-color tilework with flower and bird motifs as well as mo’arraq tilework. As with Ivan, the introduction of domes into Islamic architectural designs was done by the Persians. The Persians had constructed such domes for centuries before, and some of the earliest known examples of large-scale domes in the world are found in Iran. The Safavid muslims borrowed heavily from pre-Islamic knowledge in dome-building; i.e. the use of squinches to create a transition from an octagonal structure, into a circular dome. To cover up these transition zones, the Persians built rich networks of stalactites. Thus, came also the introduction of this feature into Persian mosques. In the center of the great prayer hall look out for a few black paying stones underneath the dome, which when stamped upon create seven clear echoes. The fact that sound is equally carried to all parts of the dome chamber and cloisters on each side as well as to the courtyard and the lateral porches indicates that four centuries ago Iranian architects were able to produce buildings provided with acoustics, not inferior to those of any modern building. The Mosque has been registered along with Naqsh-e Jahan Square as a UNESCO World Heritage Site. In building this structure, the architects also employed a great deal of marble, which were gathered from a marble quarry in nearby Ardestan. Throughout the building, from the entrance portal and to the main building, the lower two meters of the walls are covered with beige marble, with beautifully carved poles at each side of every doorway and carved inscriptions throughout. Above this level begins the mosaic tiles that cover the rest of the building.