The ancient Romans were master builders and pioneers of architectural engineering. Over 2,000 years after the height of the Roman Empire, its architectural legacy endures in the form of stunning buildings, monuments, and facilities that still stand today across Europe, the Mediterranean, and North Africa. As a historian, I‘m awed by the Romans‘ ability to construct immense, complex stone structures that have withstood the ravages of time. Their creations provide a fascinating window into Roman culture, society, and daily life.
From gladiatorial amphitheaters to temples to aqueducts, many iconic symbols of the Roman Empire remain to explore today. Here are 10 of the most incredible and well-preserved ancient Roman structures you can still visit:
1. The Colosseum – Rome, Italy
Perhaps no structure symbolizes the Roman Empire at its height more than the epic Colosseum. Construction on this massive amphitheater began under Emperor Vespasian in 72 AD and was completed in 80 AD under his son Titus. The Colosseum held over 50,000 spectators who gathered to watch gladiatorial contests, animal hunts, executions, and dramas.
The Colosseum measures 620 by 513 feet (189 by 156 meters) and stands 157 feet (48 meters) tall. It was the largest amphitheater ever built at the time and remains the largest standing amphitheater today. The Colosseum incorporated numerous architectural innovations, including an elaborate substructure and over 80 entrances to allow the immense crowds to enter and exit quickly.
As historian Keith Hopkins noted in his book "The Colosseum," this iconic structure served as "a vast stage for the public display of Roman power and popular entertainment." It was a monument meant to project strength and a gathering place that unified society. Today, an average of 7.6 million people visit the Colosseum each year. It endures as an awe-inspiring testament to Roman engineering and an artifact of the spectacles that both entertained and shaped Roman society.
2. The Pantheon – Rome, Italy
The Pantheon is not only one of the best preserved ancient Roman buildings but a major milestone in architectural history. Built around 125 AD by Emperor Hadrian, the Pantheon has been in continuous use for nearly 2,000 years.
The most remarkable feature is the giant domed ceiling, which measures 142 feet (43 meters) in both height and diameter. Until the 20th century, the Pantheon‘s dome was the largest in the world. The demand is a perfect hemisphere resting on a cylinder, with an oculus in the center that lets in natural light. The genius of the design is that the thickness progressively decreases from bottom to top, with the basement walls 21 feet thick but the walls at the oculus only about 4 feet thick.
As a temple dedicated to all the gods, the Pantheon was an important religious center. But its legacy extends far beyond that; the Pantheon pioneered important architectural innovations, like the use of concrete, arches, and domes, that influenced countless subsequent buildings. Famed historian Ranuccio Bianchi Bandinelli called it "one of the great masterpieces of architecture of all time, both for its imposing overall effect and for the rationality and harmony of its individual parts."
3. Hadrian‘s Wall – England
Hadrian‘s Wall is one of the most impressive examples of Roman border fortifications and a fascinating artifact of the Roman occupation of Britain. In 122 AD, Emperor Hadrian ordered the construction of an immense wall stretching 73 miles (117 km) from coast to coast across northern Britain. The wall marked the northernmost frontier of the Roman Empire for nearly 300 years.
Hadrian‘s Wall averaged around 10 feet wide and 15-20 feet tall in most places. It included 16 major forts plus 80 smaller forts called milecastles, with two observation towers (called turrets) between each milecastle. At its peak, Hadrian‘s Wall may have been manned by around 9,000 soldiers, customs officials, and their support personnel.
As historian Guy de la Bédoyère wrote, "Hadrian‘s Wall was a potent symbol of the power and resources which Rome could command…a statement that here was the very edge of civilization, beyond which lay an untamed wilderness." Today, you can still walk long stretches of Hadrian‘s Wall, which endures as the largest remaining Roman artifact in Britain and a UNESCO World Heritage Site.
4. Aqueduct of Segovia – Segovia, Spain
The Aqueduct of Segovia is a stunning testament to Roman hydraulic engineering and building prowess. Likely built around the 1st century AD (though some date it to the reign of Emperor Domitian in the late 1st century), the aqueduct carried water over 10 miles (16 km) from the Frío River to the Roman city of Segovia.
The most iconic section is the visible aqueduct structure in Segovia itself, which features a staggering 167 arches over 2,500 feet (800 meters) long and nearly 100 feet (28 meters) tall at its highest point. Remarkably, the entire aqueduct was built without mortar; the granite blocks hold together entirely by ingenious precision fitting.
The aqueduct operated for centuries, with some sections still in use as late as the 19th century. It‘s a remarkable feat of ancient engineering. As professor Horace Sandars wrote in 1905, "Of all the monuments left to us by the Romans none is more striking or more characteristic than the Aqueduct of Segovia… a witness to the solid structure and the far reach of that Empire."
5. Maison Carrée – Nîmes, France
The Maison Carrée (Square House) in Nîmes, France is one of the best preserved Roman temples anywhere, a pristine example of classical architecture. The temple was built around 16 BC, probably to honor Emperor Augustus‘ grandsons Lucius and Gaius.
The Maison Carrée is a textbook example of the Roman temple style, with a deep porch supported by Corinthian columns, a single cella (interior room), and elaborate exterior carvings and embellishments. It measures 85 feet long by 44 feet wide and 50 feet high (26m by 13m by 15m).
That the Maison Carrée survived in such good condition is remarkable, owing to the fact that it was in continuous use over the centuries as a meeting hall, stables, a church, and a museum. It‘s a highlight of Nîmes, a city studded with well-preserved Roman sites like the amphitheater and aqueduct bridge. Famed architect Frank Lloyd Wright praised the Maison Carrée as "one of the most beautiful buildings of all time."
6. Diocletian‘s Palace – Split, Croatia
Few ancient Roman sites let you experience immersion in a classical landscape like Diocletian‘s Palace in Split, Croatia. Roman Emperor Diocletian built this massive seaside complex as a fortified palace/retirement residence, and moved there in 305 AD after his abdication.
The rectangular palace complex measures 705 feet (215 m) from east to west and 590 feet (181 m) from north to south, encompassing 9.5 acres. It included a military garrison, imperial apartments, three temples, and extensive substructures.
After the fall of the Roman Empire, the palace was gradually transformed into a town as homes, businesses, and churches sprouted within the ancient walls. Today, Diocletian‘s Palace forms the historic heart of Split, with an incredible mix of ancient Roman, medieval, and modern buildings. You can still walk the original Roman streets, gaze up at the monumental arches and columns, and even visit the subterranean chambers.
Diocletian‘s Palace is a microcosm of the living legacy of Roman architecture. As historian J.J. Wilkes put it, "The palace represents the utmost that Roman technology could achieve in a building that was quite unlike anything else then surviving from classical times."
7. Amphitheatre of El Jem – El Djem, Tunisia
Ruins of the Amphitheatre of El Jem showcase the geographic reach of the Roman Empire and its architectural influence. Built around 238 AD, this massive arena was the third largest amphitheater in the Roman world after the Colosseum and Capua.
The amphitheater measures 489 feet (149 meters) long and 396 feet (121 meters) wide, with a stone block and concrete structure rising 112 feet (34 meters) high. In its heyday, it could hold up to 35,000 spectators of gladiatorial contests, chariot races, and performances.
The structure fell into disuse after the Roman period but remained fairly intact over the centuries, even being used at one point as a fortress. Extensive restoration work in the 20th century returned the Amphitheatre of El Jem to pristine condition; it now stands as one of the most impressive and complete Roman ruins in the world. UNESCO calls it "an exceptional illustration of Roman architecture, especially of the design and construction of such a large-scale building."
8. Basilica Cistern – Istanbul, Turkey
One of the most fascinating but often overlooked ancient Roman sites lies deep underground in Istanbul – the Basilica Cistern. This subterranean marvel was built by the Romans in 532 AD as a large public water storage facility for the city of Constantinople.
The chamber measures 453 feet (138 meters) long by 213 feet (64.6 meters) wide. The roof is supported by a forest of 336 intricately carved marble columns, each 30 feet (9 meters) tall, arranged in 12 rows of 28. With the endless columns, subdued lighting, and a few feet of water on the floor, the Basilica Cistern is an eerie, otherworldly space.
At its peak, the Basilica Cistern held nearly 3 million cubic feet (78,000 cubic meters) of water delivered via 12 miles of aqueducts from a reservoir near the Black Sea. It was part of a complex system that allowed Constantinople to flourish for centuries. As urban infrastructure goes, there‘s still nothing quite like it in the modern world.
9. Trier Imperial Baths – Trier, Germany
The extensive ruins of the Imperial Baths complex in Trier reveal just how important public baths were to daily life in a Roman city. Built around the 4th century AD, these thermae were some of the largest bathing complexes outside Rome, covering an area of 172,000 square feet (16,000 square meters).
The Imperial Baths included an immense frigidarium (cold baths), a multi-room tepidarium (warm baths), and a caldarium (hot baths) heated by a furnace room that sent hot air flowing through a hypocaust system under the floor and between double walls. In Roman times, several hundred citizens would move through this bath circuit each day, not just for hygiene but as an important social gathering.
You can still explore the labyrinthine ruins of the bath chambers, service tunnels, and heating system. Details like marble steps, mosaic fragments, and carved reliefs hint at the opulence of what were essentially Roman leisure centers and community hubs. Professor Garrett Fagan, a leading expert on Roman baths, called the Imperial Baths of Trier "perhaps the most impressive surviving bath complex from the ancient world."
10. Verona Arena – Verona, Italy
The Verona Arena stands out among ancient Roman amphitheaters for its remarkable state of preservation and the fact that it still serves as a functioning entertainment venue. This stunning arena was built in the 1st century AD in the Roman city of Verona.
The stone and marble structure measures 456 feet (139 meters) long and 404 feet (123 meters) wide, with an arcade rising to 98 feet (30 meters). In Roman times it held up to 30,000 spectators. While the outer arches have been damaged by earthquakes over the centuries, the interior is largely intact down to many of the original seats.
The Verona Arena has hosted performances and shows almost continuously over the centuries. Today it‘s best known for the large-scale opera productions held there each summer. Experiencing a performance in this ancient Roman venue, surrounded by stone arches under a starry sky, is an unforgettable link to the past.
These 10 sites are among the most stunning examples of ancient Roman architecture and engineering still standing today. But they represent just a fraction of the Roman structures and ruins that dot the landscape from Scotland to Syria, a testament to the vast spread and influence of the Roman Empire.
What‘s most remarkable about these structures is not just their beauty and complete forms, but the incredible complexity and innovation behind them. The Romans pioneered the use of architectural elements like arches, vaults and domes, as well as construction materials like concrete, enabling them to create buildings on a entirely new scale.
At the same time, the amphitheaters, public baths, aqueducts and other large civic works provide a fascinating lens into Roman culture and daily life. They reflect a society with a strong communal nature, where massive venues allowed citizens to come together for entertainment, leisure, and shared experiences.
The legacy of ancient Roman architecture echoes through to the present day. As historian Diana DePardo-Minsky wrote, "Almost every style of Western architecture, from Romanesque to Gothic to Renaissance to Neoclassical and beyond, bears a huge debt to the designs and structures invented by the Romans." You can see the influence in iconic buildings like the U.S. Capitol and White House.
Perhaps above all, these enduring Roman buildings inspire a sense of awe at human ingenuity, artistry, and ambition. They‘re a vivid reminder that, as the 1st century BC Roman architect Vitruvius put it, "Architecture is a science arising out of many other sciences, and adorned with much and varied learning." Nowhere is that more apparent than the stone wonders the ancient Romans left behind.
