Built during the Safavids period, it is an excellent example of the Islamic architecture of Iran. Many people see it as the masterpiece of Persian Architecture. The Imam Mosque of Isfahan is one of the everlasting masterpieces of architecture in Iran and all over the world. It is registered along with the Naghsh-i Jahan Square as a UNESCO World Heritage Site. Its construction began in 1611. Its splendor is mainly due to the beauty of its seven-color mosaic tiles and calligraphic inscriptions.