The Sorbonne Chapel

The Sorbonne Chapel, a masterpiece of French Classicism, opens the second half of the tour. Its defining feature is the central dome, a landmark of the Latin Quarter. Influenced by St. Peter's Basilica in the Vatican, it has a Roman-style lantern, a small tower atop the dome, and it went on to shape Les Invalides and later church architecture in France.

■ The west façade The west façade has Corinthian columns on the ground floor. The second story is narrower, with flat pilasters set against the wall, and the whole is marked by symmetry and balanced proportions. The shield above the clock bears the coat of arms of Cardinal Richelieu's family, topped by a wide-brimmed cardinal's hat. The muses beside the clock stand for learning and the arts. The statues on either side are Saint Thomas Aquinas on the left and Peter Lombard on the right, with Gerson below left and Bossuet below right, a reminder that the Sorbonne grew out of a theological college.

The chapel is the only surviving part of the 17th-century Sorbonne, and it's joined to the university buildings. The west façade stands where citizens of the day first saw the university. Cardinal Richelieu, who was its head, was an ambitious man who wanted to build up learning and theology to rival Rome. The entrance was meant as more than a church door: it announces that this is France's leading center of learning and faith.

■ Richelieu's tomb If you see one thing inside, make it Richelieu's tomb. Planned from the chapel's earliest design, this marble monument took 20 years to make. The half-reclining figure in the center is Richelieu. His gaze toward the altar is said to express faith in resurrection and eternal life. The figure at his head personifies Religion in grief, and the one at his feet personifies Learning, mourning the cardinal's death.

■ Getting to the next stop Next is Saint-Séverin, the second-longest walk on the tour. With the Sorbonne Chapel in front of you, head down the lane to the left. At the end, cross toward the Musée de Cluny straight ahead and turn left along the museum. Where the building ends, turn right and keep going. When you reach the road, cross from the RER station toward McDonald's, then turn right and take the first lane. The spire on the right at the dead end of the lane is Saint-Séverin. Obey the signals and watch for bikes and cars when crossing. It takes about eight minutes, and we'll tell you about Alexandre Dumas along the way.