The name means "pattern of the world" and indeed is in-keeping with the well known Farsi saying "Esfahan nesf-e Jahan" which means "Esfahan is half the world".
The square was begun in 1602 under leadership of Shah Abbas 1st as the centrepiece of his new Capital. In those days it was used for Polo matches which the Shah would watch from the adjacent Ali Qapu Palace.
It is the second largest square on earth and is a world heritage site.
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Naqsh-e Jahan Square with the Sheikh Lotfollah mosque