"Pisa’s famous leaning tower (the campanile of the adjacent Duomo) is part of the Piazza del Duomo, a UNESCO World Heritage Site that also includes the Duomo, baptistery and cemetery. Begun in 1173, the tower began to lean almost immediately thanks to soil subsidence. To try to halt the tilt, cables and counterweights have been inserted. A spiral staircase with nearly 300 steps leads to the top of this unique, iconic building."
What to Do in Tuscany
