Il Duomo - Cattedrale de Santa Maria del Fiore
Florence's most popular site is its Duomo (cathedral), the Cattedrale de Santa Maria del Fiore. The huge Gothic duomo was begun in 1296, consecrated in 1436, and holds 20,000 people. The exterior, made of green, pink, and white marble, has several elaborate doors and interesting statues. Inside, Brunelleschi's Dome is a masterpiece of construction. Buy a ticket to climb the 463 steps to its top. To go inside, cover arms and legs. The Duomo is in Piazza del Duomo, free admission
Last year Italy passed a law that everyone using public internet must present an identity document. So when you go to Italy, be prepared to show your passport before using the internet. They will make a photocopy of the passport or record your name and passport number. We were told that this is aimed at increasing security and preventing terrorism.
On the first day, do the "Caesar Shuffle" from the Colosseum to the Forum, then over Capitol Hill to the Pantheon. After a siesta, join the locals strolling from Piazza del Popolo to the Spanish Steps (see my recommended "Dolce Vita Stroll," in Rick Steves' Rome). Have dinner near your hotel. On the second day, see the Vatican City (St. Peter's, climb the dome, tour the Vatican Museum). Have dinner on the atmospheric Campo de' Fiori, then walk to the Trevi Fountain and Spanish Steps (see my recommended "Night Walk Across Rome," in Rick Steves' Rome). With a third day, add the Borghese Gallery (reservations required) and the National Museum of Rome