Anyone can rattle off a list of fun facts, such as the total population of a city or its local currency, after a quick search on Wikipedia. But what truly informs the character of a place are its most unique and eccentric elements. From unlikely street art to a gallery that’s inaccessible 364 days a year, here are seven things you probably didn’t know about Lisbon, Portugal.

It’s not officially the capital

Until 1255, Portugal’s King D. Afonso III called the city of Coimbra home. However, attracted by the wide harbors and increased development in Lisbon, he packed up his stuff and moved to the coastal city in the south. Every ruler since then has remained in Lisbon. The only problem? None of them ever signed an official document declaring it the country’s capital. Of course, that doesn’t really have any real-world consequences, but unlike most countries, Portugal has only a de facto capital.

Its best attraction is open just one day a year

At the end of every summer, a group of specialized personnel gather in downtown Lisbon, duck into a hole in the Rua da Prata, and work for weeks on end — sometimes an entire month — to clear out the flooded area beneath the street. Their efforts reveal an underground Roman gallery dating back to the reign of Augustus. When the monument finally opens to the public, it lasts just a few hours before becoming inaccessible again. Admission is free, but you’ll most likely have to wait in line, as crowds of both locals and tourists gather for the ephemeral emergence of this beautiful gallery.

It encourages street art

In many cities, graffiti is but an inconvenience, a chaotic barrage of vandalistic scrawls that must be continually power-washed away. But in Lisbon, graffiti is art. The creations found on the sides of its buildings are both beautiful and daring. Particularly ubiquitous artists, such as Bordalo II and Vhils, have even become well-known Portuguese names. As you walk about the city, take time to admire the murals, portraits, and tags adorning every wall and alleyway.

It hosts a marvelous marathon

Do you enjoy running agonizingly long distances plagued by strained muscles, shortness of breath, and the pressure of a ticking clock? Really? Well, then marathons might be for you. And as long as you plan to put yourself through that torture, why not do it on one of the most gorgeous courses in the world? Lisbon’s marathon begins at the coastal village of Cascais and follows the banks of the Tagus before concluding at the Praça do Comércio in the race’s namesake city. Plus, it’s called Lisbon’s Rock ‘N’ Roll Marathon because live musicians play along the course to help take the runners’ minds off the unfathomable amount of pain they’re putting themselves through. So, rock on!

It boasts the longest bridge in Europe

Built to commemorate the 500th anniversary of the eponymous explorer’s return from India, the Vasco da Gama Bridge stretches over 10 miles (17 kilometers) and connects the northern and southern parts of the country, making it the longest bridge on the continent. It’s so long that, unless you’re blessed with clear skies, you can’t see from one side to the other. The bridge required 3,300 workers and 18 months to complete. Still not impressed? In 1998, 16,000 people gathered on the bridge and sat down for a meal, officially setting the record for world’s largest dining table.

It’s said to be built upon seven hills

This isn’t as unique as it might sound. In fact, over 50 cities boast the same claim to fame. What makes it interesting, however, is that it’s believed that Lisbon joined the list after the Roman soldiers who were stationed there noticed similarities between the two capital cities. Rome, after all, is the “original” city of seven hills. Lisbon’s mounds are named Castelo, São Vicente, São Roque, Santo André, Santa Catarina, Chagas, and Sant’Ana, though you might not be able to distinguish all seven from one another. What you will notice is how tired your feet get after exploring this hilly city!

Its streets are beautiful

With all of the terrific architecture scattered across the capital, you’ll be tempted to keep your head craned to the sky. But don’t forget to look down occasionally as well. You’ll be mesmerized by the calçada Portuguesa — or, Portuguese pavement. The term refers to white-and-black limestone laid around Lisbon in a mosaic style. The result is a city in which even a casual stroll becomes a walk through a brilliant gallery of art.

Cover Photo by Derek Stewart