What makes the city of Grammichele unique is its hexagonal plan. Starting from the large central square, alleys and streets branch off that give it this shape.
The town was founded after the great Sicily earthquake of 1693 wiped out an earlier settlement called Occhialà, located to the north of modern Grammichele.
Grammichele was built by Carlo Maria Carafa Branciforte, the Prince of Roccella and Butera. Designed by Michele da Ferla, it was the first city in Europe with a hexagonal plan. Its layout was probably inspired by Palmanova, a fortified town built one hundred years earlier.
Grammichele has a hexagonal plan that could be potentially extended indefinitely. The hexagonal plan designed for Grammichele is divided into six sectors by six roads all converging towards the main square, that is hexagonal too, on which public offices overlooked.
Source(s) and Inspiration(s):
Rashid's Blog: A Place for Inquisitive Souls 