The cathedral (or duomo in Italian) dedicated to Santa Maria del Fiore is in the old town. Dates from the fourteenth century and is famous for its large dome, which is 45 m in diameter and 100 in height. It was designed by Brunelleschi. The interior contains frescoes by Giorgio Vasari that represent the end of the world. The building of gigantic dimensions, has a Latin cross plan. The floor is covered with colored marble which is a maze of shapes and textures. Except for the dome and ceramic orange roofs, walls of the temple are covered with marble Tuscan white, green and pink.

A feature of many churches in Italy is that the bell tower is attached to the church, but separately, a few meters from it. The campanile of Florence was designed by Giotto and is completely covered by colorful Tuscan marble.

Right in front of the cathedral is the magnificent baptistery.