The patron saints of Grammichele are Saint Michael the Archangel and Saint Catherine of Alexandria, celebrated on 8 May and honoured in the town's cathedral. The town is named after the place where the inhabitants of Occhiolà, the ancient Sicel Echetla or Eketla, moved after it was destroyed by the earthquake of 11 January 1693: three months after the quake, Prince Carlo Maria Carafa Branciforte founded the new settlement on his own fief, about two kilometres from the Occhiolà hill.
The work of the same prince, assisted by friar Michele da Ferla, is the hexagonal layout of the new town, an urban planning choice also adopted in Avola and remaining a rare example of rational architecture in Italy: the perimeter is a hexagon with a likewise hexagonal square at its centre, home to the mother church and the town hall, from which five ring roads radiate along with six perpendicular ones leading to as many rectangular squares.
