Notre Dame is not Paris' greatest church; make Sainte-Chapelle your first sightseeing priority

Day three in Paris was supposed to be devoted entirely to the Louvre. Not only is it a blockbuster site, but it has a checked baggage facility and sits a stone's throw from the RER station that takes you to the airport. A perfect occupation for a day ending with a return flight.

We were, however, shy of crowds after the horrors of Versailles the day before. The idea of spending another day standing in queues, packed with the rest of the sightseeing throng, didn't appeal. We wanted a gentle, relaxed time. A day that would leave a soft, warm Parisian glow in our bellies as we stepped on that plane to London. And that's just what we got.

We started at my favourite Gothic building in Paris, the Sainte-Chapelle. The royal palace that once surrounded it has been replaced by government buildings, making it a bit of a hidden jewel; you need to seek it out, as you're unlikely to stumble upon it from this corridor of bureaucracy a stone's throw from Notre Dame. Built in the early 1240s to house an impressive pack of relics King Louis IX (later St. Louis) bought from the Holy Land, it is an exquisite, jewel-encrusted reliquary writ large. It's a riot of colour from its magnificently polychromed statues and columns through its wonderous windows to its lapis-infused blue ceiling mimicking the heavens with golden stars.

It's actually two chapels, with the one for the common people on the ground floor. The lower chapel is spectacular on its own, with gold, enamel and jeweled quatrefoils showing bible scenes and walls painted to copy rich materials. But it's just a visual amuse bouche for what's ahead. You dive into a dark, featureless spiral stair, climb four rotations and come out into the vivid magnificence of the upper chapel, where the windows are so dominant you hardly notice there's a stone framework to hold them in place. A great medieval church strove to create a vision of heaven on earth, elevating people from their mundane lives to a higher plane filled with mystery, awe and beauty. I don't think there's a religious building in France that does this better than Sainte-Chapelle.

Of course, the church everyone heads for immediately in this town is Notre Dame. I could hardly contain my disappointment when I first saw it, caked with urban grime on the outside, dark within and much smaller than expected. By this time I'd taken in the splendors of Westminster Abbey, Salisbury, Lincoln, King's College chapel in Cambridge ... all magnificent buildings that had the advantage of studying from Notre Dame's early innovation (notably pointed arches and flying buttresses) and then improving upon it. But the French have recently finished cleaning up this architectural matriarch, and she's looking grand. With the exterior sparkling white, it's much easier to appreciate the multitude of sculpted saints, the stone tracery and the famous gargoyles.

Inside, we benefited from three things. First, it was still early enough for the crowds to be manageable. Second, it was a sunny day. The windows don't dominate the walls here as they do in later Gothic churches, but those that do cut through the stone are gorgeous. While Sainte-Chapelle is almost exclusively blue in its glass, Notre Dame ads a heart-stopping red to the mix, like liquid rubies when the sun filters through. Third, it was All Saints Day and we were there during high mass, with a full complement of formally robed priests using some of the fine ornaments from the treasury and a choir adding a sacred soundtrack. Notre Dame is a stage set, after all, and on this day they were putting on the show. Any building works better when it's being used for its original purpose.

After that, it was time to introduce Piers to another of my Parisian favourites, the Marais. Versailles set the model for palaces, Notre Dame formed the template for the Gothic, and it's the Place des Voges in this district that set the model for every sophisticated urban square that followed. London architecture as we know it today simply wouldn't exist without this 17th century innovation in town planning. Today it's one of the most beautiful bits of the city, filled with elegant homes and high end shops, usually enlivened by the jazz quartet Borsalino, who seem to have become a regular fixture.

From here it was a wander down the Rue des Francs-Bourgeois, where the street level view is of cool clothing boutiques and funky jewelry shops, while a lift of the eyes reveals a wealth of 17th century aristocratic homes. With our mutual interest in history, the Musee Carnavalet would have been the perfect place for us to spend the afternoon, were it not closed on Mondays. So after getting a feel for the area, the logical next step seemed to be a leisurely lunch. (Check in tomorrow for the restaurant roundup.)

After lunch, the clock was ticking. We had 90 minutes before we needed to be picking up luggage back at the hotel. Time, it seemed, for one more church.

La Madeleine is a neoclassical pile just off the Place de La Concorde. From the exterior, it's distinguished by its exact resemblance to a Roman temple, imposing Corinthian columns atop a solid stone platform holding up a highly decorated pediment. And also by its position opposite its matching building, the Asemblée National, sitting on the other side of the Seine across the Place. The interior is less impressive, mainly because the line of coffered, oculus-pierced domes that run down the nave are dark, dirty and desperately in need of renovation. This brings a touch of gloom to the whole place. Looking past that, however, you see the strict neoclassicism continued in here. The statues in the niches could just as easily be Jupiter, Juno and Mercury as the saints who stand there today. The most unique element of the interior, however, is the distinctly un-Roman organ, which has seen a long line of famous musical directors including Saint-Saëns and Gabriel Fauré. The church regularly hosts concerts and we were lucky enough to be wandering while the organist was in full flow. As with Notre Dame, the music transformed the experience.

And then it was all over. The clock hit 4:30 and it was time to grab luggage and head for the airport. We'd rolled a massive amount of sightseeing into three days, but not so much that we'd exhausted ourselves. Primarily because each night we refreshed ourselves with some truly fine dining. To read about that, you'll have to come back tomorrow.