Ralph Waldo Emerson once said, “Be an opener of doors.” Good advice for anyone who wants to learn, see, discover, experience, explore. But we shouldn’t forget to stop and take a look at the door itself. The best ones are works of art in and of themselves, loaded with history and character. As a unit, the colorfully painted Georgian doors in Dublin are unbeatable, and the doors all around Tenerife in the Canary Islands that are painted green to ward off evil spirits are terrifically curious. But individually, these are my favorites.

#1 Cathedral of St. Domnius (Split, Croatia)

This magnificent cathedral in the heart of ancient Split has always had it all, right from its wonderfully ironic beginning. Situated in what was the retirement palace of the Roman emperor Diocletian (which covered 320,000 square feet), the cathedral’s oldest part is a third-century mausoleum designed as a shrine to the emperor, who oversaw what was eventually to be called the Diocletianic Persecution—the empire’s last and most vicious persecution against Christians, lasting from 303 to 311. More than 300 years later, when Christian refugees fled to this area, they removed Diocletian’s remains, converted the mausoleum into a Christian church, and dedicated it to St. Domnius, a bishop who had been beheaded by Diocletian in 304. Poetic justice served! Inside, I found a wonderful pulpit from the 13th century, a high altar from 1427, and a canopied Gothic altar from the 15th century. I climbed the 179 stairs of the 200′-tall bell tower from the 16th century to take in fantastic views of the city and the Adriatic Sea. But I almost never got to any of that because I was frozen in my tracks by the magnificent artwork on the two front doors before I even stepped inside. At just over 17′ tall, the doors are adorned with more than two dozen scenes from the life of Jesus carved in wooden relief, starting with the Annunciation and then Christ’s birth and ending with the Crucifixion and Ascension. A different intricate pattern of interwoven tracery frames each scene, and each one of those is separated from the others by highly detailed acanthus and grape vines, with small human and animal figures detectable in the leaves. The doors are not only gorgeous (they’re the finest Romanesque sculptures in all of Croatia), they’re also remarkably preserved. Aside from a little deterioration at the bottom, perhaps from splashes of rain on the ground, the doors remain in outstanding condition—not bad for carved wood that’s exactly 800 years old.

#2 Cathedral of St. Nicholas (Ljubljana, Slovenia)

Completed in the first decade of the 1700s, the stunning yellow Cathedral of St. Nicholas is just steps from the Central Market, the Ljubljanica River, and the lovely Triple Bridge. With its gorgeous ceiling, gilded organs, and detailed frescoes, it’s one of the most beautiful buildings in the city. And to enter it, you have to open one of two magnificent bronze doors adorned with raised relief sculptures. Although they appear to be as old as the rest of the church, both doors are new additions to the cathedral, replacing the older versions shortly before a visit by Pope John Paul II in 1996. The side door, named the Ljubljana Door, depicts the history of the Ljubljana diocese, with six 20th-century Ljubljana bishops wearing mitres and standing above the enshrouded body of Christ. The main door, called the Slovene Door, was commissioned to commemorate 1,250 years of Christianity in Slovenia. At the very top, Pope John Paul II peers down from a window at such scenes as the Crusades and the independence of Slovenia in 1991. But how do you open these doors, as both lack a doorknob or handle? Part of the sculpture itself serves as the grip, now worn a shiny gold from thousands of human hands grasping them to enter this outstanding house of worship.

#3 Duomo (Pisa, Italy)

Part of the Piazza dei Miracoli, the cathedral in Pisa occupies the central position in a winning trifecta that also includes the Baptistery and that famous leaning tower. Begun in 1064 around the time Pisa was peaking as a major force on the Italian peninsula, the cathedral features four rows of open galleries with columns and Romanesque arches, the uppermost level topped by a statue of the Madonna holding a child Jesus. Brown and orange discs highlight the gray marble and white stone of the façade. Below each lunette brightened by mosaics are the bronze doors made in the 1600s following a fire in 1595 that destroyed the existing doors. On the two side doors, reliefs with exquisite details—from the feathers of an angel’s wings, to the creases in a robe, to locks of hair—show scenes from the life of Christ, while those on the central door depict the life of Mary. This enduring work of art came from the workshops of the Flemish sculptor Jean Boulogne (also known as Giambologna), who was so talented that the Medici family forbade him from ever leaving the area, fearful that the Austrians or Spanish Habsburgs would tap him for such works of beauty in their own lands.

#4 House of the Blackheads (Tallinn, Estonia)

The Brotherhood of the Blackheads in Tallinn was a guild for unmarried shipowners and merchants founded in 1399 primarily as a military organization (yet one of its duties during its early years was to place a Christmas tree in the square in front of the town hall every December, making Tallinn the first European city to establish the tradition of displaying a public Christmas tree). Following the Great Northern War in the early 1700s, the non-military aspects of the organization gained priority, and it remained a largely social institution until it was dissolved by the occupying Soviets in 1940. The Blackheads built their headquarters in 1532—a four-story gabled edifice that remains the only Renaissance building left standing today in Tallinn. Surrounded by highly detailed sculptures in stone, the single entry door from the 1640s is an eye-catching site along the cobblestone Pikk Street. Painted green with diagonal red-orange stripes, the door features an asymmetrical arrangement of gold florets, a simple black iron door knocker, and a rather old keyhole. Above the door in the lunette span under the rounded arch, two gold masks rest on either side of a painted sculpture of a profile of the Moorish St. Mauritius, the third-century leader of the Roman Theban Legion who became the brotherhood’s patron saint.

#5 Washington State Capitol (Olympia, Washington)

Constructed from 1922 to 1928, the Washington State Capitol boasts the fifth-tallest masonry dome in the world, weighs more than the Washington Memorial in Washington, D.C., has more solar panels than any other U.S. capitol, and has survived three major earthquakes. It’s a particularly handsome building to explore, approached by 42 stairs, reflecting Washington’s entrance into the Union as the 42nd state. The gorgeous interior contains the largest collection of Tiffany bronze in the world and a stunning 10,000-pound chandelier. Under the protection of the portico, I closed my umbrella on my third day of typically wet weather and studied the six beautiful and large cast-bronze doors at the entrance. Each door weighs five tons and each bears one wonderfully evocative relief image of early industry and scenic beauty of Washington State over a bronze lion-head doorknocker: a sailing ship, a waterfall in a pine forest, a flock of sheep, a team of oxen hauling logs out of a forest, the territorial capitol building, and an early homestead. I was the only one enjoying this mini-history lesson, as soggy politicians hurried by on the way to their chambers, delighted by what something so simple as a door can do.

Five Runners-up

• Cathedral Church of St. John the Divine (New York, New York)
• St. Fin Barre’s Cathedral (Cork, Ireland)
• Warner Chamber, Nebraska State Capitol (Lincoln, Nebraska)
• St. Bartholomew’s Church (New York, New York)
• Cathedral of the Immaculate Conception (Wichita, Kansas)