My favorite are the gray cobbles used throughout Rome. Locals call the three-inch-square paving blocks, “San Pietrini,” little Saint Peters, playing on St. Peter’s role as the rock of Christianity. In his landmark De Architectura, or The Ten Books of Architecture, Vitruvius referred to the lava that made the stones as hard, enduring rock, calling it siliceae, or silex.
San Pietrini in La Piazza del Popolo, Rome
More exotic cobbles are found in Seravezza, one of the great localities for marble in Italy. It was here around 1519 that Michelangelo went in search of white marble for the façade he had designed for the church of San Lorenzo in Florence. The church was never built but Michelangelo did open up quarries still used at present. In the sidewalks of Seravezza, you can find a wide variety of the many colors of marble quarried in the Apuan Alps.
Marble paving stones of Seravezza
In the town of Volterra, about 30 miles southwest of Florence, are massive paving stones. Volterra is a classic Tuscan hill town with a history that stretches back to Etruscan times. The Etruscans built several gates, one of which remains and still has figures carved out of basalt, though much weathered. The well-worn roads are made of sediments rich in fossil shells, the largest of which are the size of a deck of cards.