SOMEHOW, I MISSED BELGIUM the first time around. When I was 18, my college boyfriend, Larry, and I backpacked through Europe, shivering in our tent beside Scandinavian fiords and picnicking on bread, cheese and wine around campfires on the fringes of Amsterdam, Paris, Rome and Vienna. Belgium wasn’t even on our radar.

I’ve spent many vacations since that collegiate Wanderjahr exulting in the grown-up pleasures of traveling through Europe (sleeping in hotels and eating in restaurants, among them) with Larry, now my husband, not once considering Belgium as a destination.

This past summer, our youngest child, Anatol, was interning at the European parliament in Brussels, and, of course, we went to visit him. Traveling to a completely new European capital at my age made me feel a little young and a little stupid, but in a good way. After years of revealing some of our favorite parts of the world to Anatol, Larry and I liked the idea of letting our son show us around.

We recognized the effect of Anatol’s Belgian cultural immersion right away, when, on our first morning in Brussels, he picked us up at our hotel and took us directly to his favorite chocolate shops, warning us that the experience would change our lives. (He knows his parents too well.)

La Maison Wittamer Photo: Natalie Hill for The Wall Street Journal

We stepped under the signature pink awning of La Maison Wittamer to find gleaming vitrines displaying chocolates in every shade, including tiny mosaic works of art with colorful, sparkling surfaces. But nothing prepared us for the chocolates that were filled with crème fraîche—delicate and sumptuous creations made every other day. Anatol bought a bag and we passed it around right in the store, biting into the chocolate shells that shattered to release tiny torrents of sweet cream across the tongue. Anatol was right: Our lives were changed.

With breakfast out of the way, we wandered. My husband is a European historian and had armed himself for the trip with several guidebooks and a number of scholarly volumes, but Anatol took his chaperone responsibilities seriously, and not just in terms of chocolate.

“I work here,” Anatol said proudly, as we stood in a plaza surrounded by the curving, elevated causeways of the modern European Union Parliament building. “This is the political center of Europe,” he explained. It was not, however, the center of Brussels, which he told us was the next stop on our itinerary.

The Grote Markt, or Grand Place, the city’s historical center, is built around an impressive 15th-century town hall topped with a gothic spire. The baroque facades of the guild houses that line the square each display symbols of the professions that these medieval trade associations represented (fire, water and wheat for the bakers; a ship for the boatmen). The opulence of the brewers’ guild house suggested both the great wealth of the guild and Belgians’ long love affair with beer.

Everything they say about the beer in Belgium is true: There are more brands and varieties than even the most assiduous American college student could hope to sample in a summer, each served in its appropriate glass. You see the waiters going by with tall, flutelike glasses of Vedett Extra Blond that stand in contrast to the brewery’s stumpy bottles; goblets for the Waterloo Double 8 Dark (which comes in bottles decorated with scenes from the battle); and large, test-tube-like vessels filled with Pauwel Kwak, served on a wooden stand to keep them upright. I was repeatedly impressed as I ordered my morning tea in a cafe on stylish Avenue Louise, near our hotel, to see respectable citizens—young Eurocrats in their business suits and elegantly-dressed women of a certain age alike—starting their beer drinking early.

We stopped in shops along Rue Haute, in the Sablon district, which sell furnishing that range from 20th-century modernist artifacts to gilded furniture from a much earlier era. From there, Anatol took us to the Royal Museums of Fine Arts complex, which conveniently happened to be located right near the chocolate stores.

“ I was impressed to see respectable citizens drinking beer so early. ”

W.H. Auden’s famous poem, “Musée des Beaux Arts” (“About suffering they were never wrong, The Old Masters…,”) was written after a 1938 visit to the Brussels Old Masters collection, where “Landscape with the Fall of Icarus” still hangs in the Bruegel room. You can admire the painting and reflect on Auden’s interpretation of it (“how everything turns away/Quite leisurely from the disaster”). Being in Belgium made me feel alternately stupefied and stupid—I was dazzled every day by the richness around me, by the churches and the art, from the Flemish primitives to the glory of Rubens which we explored in his own home in Antwerp.

Antwerp's monumental train station Photo: Natalie Hill for The Wall Street Journal

Anatol had already been to Antwerp, but was eager to go back. “Wait till you see the city. Wait till you see the train station,” he kept saying on the half-hour train trip from Brussels. “I’ve seen a lot of train stations,” Larry said dubiously, but Anatol was right. We arrived at a spectacular domed building, lavishly decorated in stone and mosaic and glass, a monumental entry point for another city rich in history, art—and diamonds.

Antwerp was a dominant port in the 16th century and the largest city in Europe after Paris. Today, it’s the center of the international diamond trade. But we had come in search of the artistic treasures collected and left behind by wealthy merchants who made their fortunes trading in spices and jewels and silks.

One such collection is in the home of Antwerp’s greatest artist, Peter Paul Rubens, that happy family man and famous painter of luxuriant flesh. But my favorite paintings were at the Rockoxhuis Museum, a mansion that was home to Nicolas Rockox, a prominent Antwerp citizen who lived from 1560 to 1640, served as mayor of the city and amassed an art collection that has been supplemented with some choice paintings from the Royal Museum to create a “Golden Cabinet” collection that is at once intimate—you really do feel that you are in someone’s house—and full of wonders.

Larry was particularly delighted by a 15th-century Hans Memling portrait, “Man With a Roman Coin,” in which you see the head and shoulders of a Renaissance fellow, against one of those ravishing hill-and-sky landscapes. The titular man holds a metal coin with an ancient Roman profile, perhaps a comment on the Renaissance’s rediscovery of classical civilization.

Jason Lee

As a pediatrician, I tend to go for mother-child images. In the same room, I was struck by two ravishing Madonnas, both from the 15th century, one by Jean Fouquet, in which Mary is depicted with skin as white as the ermine cloak she wears; her equally pale baby stares straight ahead, while strange red seraphim surround them both. The other, by Jan van Eyck, features a beautiful Mary—much more human, in a lavishly draped blue robe, affectionately holding a lifelike squirming baby. Anatol’s favorite painting was an amazingly vivid depiction of a winter fish-market scene by Lucas van Valckenborch, in which two wealthy women in heavy black robes, white ruffs at their necks, are buying pieces of fresh salmon and smoked fish while skaters zip around on the frozen river.

We ended our day in Antwerp at the Grand Café de Rooden Hoed, a restaurant on the Oude Koornmarkt, one of the city’s many pedestrian streets. We were drawn in by the appetizing-looking mussels on almost every table and only later learned that it was the oldest restaurant in Antwerp.

The mussels we ate that night were the best we had in Belgium. They were served in big, lidded pots, which the waiters would uncover at the table to release the savory steam. We plucked the plump mussels out of their broth and enjoyed them with the appropriate accompaniments of frites and beer. As the empty shells accumulated in the pot lids, which had been placed upside down to receive the debris, our table began to resemble a Flemish genre painting. Larry and I ordered another round of beer and thanked Anatol for bringing us to Antwerp. Come to think of it, we said, thank you for bringing us to Belgium, period.

The Lowdown // Opening Your Eyes to Brussels and Antwerp

Staying There: Rooms at Brussels’ chic and central Thon Hotel Bristol Stephanie come with a private sauna (from about $115 a night, 91-93 Avenue Louise; thonhotels.com).

Eating There: Le Clan des Belges is a busy unpretentious spot with a menu that includes regional specialties and terrific steak (rue de la paix 20; leclandesbelges.com). An elegant restaurant with an inventive menu, Les Brigittines serves a delicious Scottish beefsteak; be sure to sample one of the sour gueuze beers (Place de la Chapelle 5; lesbrigittines.com).

Antwerp’s Grand Café De Rooden Hoed has an extensive menu, but you can’t go wrong with the moules frites (Oude Koornmarkt 25; deroodenhoed.be).

The Place du Grand Sablon is the chocolate center of Brussels. Wittamer’s crème fraîche-filled confections are worth the trip across the Atlantic (Place du Grand Sablon 12-13; wittamer.com). Passion Chocolat is generous with its free samples; try the praline ancienne (Rue Bodenbroek 2; passionchocolat.be).

Shopping There: Haute Antiques brings together 25 dealers in a sprawling showroom; be sure to check out the subterranean level (Rue Haute 207; hauteantiques207.be).