These 21 Iconic Structures Represent the Finest Roman Architecture and Artistry 

Built in the second half of 1 A.D. during the reign of Roman emperor Trajan, the Aqueduct of Segovia is one of the best-preserved ancient aqueducts. It was built of about 24,000 granite blocks and, surprisingly, no mortar. The two-tier structure has 165 arches, some of them more than 30 feet high.

Erected in honor of Constantine the Great’s victory over Maxentius in 312 A.D., this magnificent monument is the largest Roman triumphal arch. It is 66 feet high and about 82 feet wide, featuring architectural moldings and relief sculptures of goddesses and emperors.

This stunning Roman temple in Nîmes was built under Roman general Marcus Vipsanius Agrippa to commemorate his two sons after they passed. The imposing façade with its elaborate columns is a beautiful example of the Corinthian order. Despite its age, the building is in a great condition because it was transformed into a church in 4 A.D.

Arguably the most famous Roman monument, the Colosseum is an amphitheater built under the Flavian emperors in 80 A.D. The structure once accommodated 50,000 spectators who entered the building through 80 entrances. When the building was completed (the top floor was actually added a couple of years after the Colosseum’s completion), emperor Titus held 100 days of games in it that featured thousands of animals and hundreds of gladiators.

This awe-inspiring building in Rome is an architectural miracle and proof of the ingenuity and superior engineering skills of the ancient Romans. The Pantheon’s dome is to this day the largest reinforced concrete dome in the world. Its façade was designed in the Corinthian order with 16 monolithic columns.

The ancient Roman Forum was in the center of public life in Rome. It was where public meetings and gladiatorial combats were held, as well as where people came to shop because it was lined with open-air markets. Its most notable structures are the Arch of Septimius Severus, the Curia, the Temple of Saturn, and the Arch of Titus.

The Phoenician city of Baalbek, also known as Heliopolis, is the site of some of the most impressive surviving Roman ruins. It is home to the Temple of Jupiter, which was the largest temple in the Roman Empire and features 54 Corinthian granite columns, each 70 feet tall.

This UNESCO World Heritage Site is an engineering masterpiece that crosses the Gard River in southern France. The three-level structure is 902 feet long and 164 feet high and was built using enormous stones that were cut to fit perfectly together, eliminating the need for mortar.

Commonly known as Castel Sant'Angelo, the Mausoleum of Hadrian is a cylindrical structure built under emperor Hadrian as a mausoleum for him and his family. It was later converted into a fortress and a papal palace, and now serves as a museum.

The small mausoleum of Galla Placidia may not have the grandest of façades but once you go inside, the sight before your eyes will blow you away. The ceiling of the building is covered in stunning mosaics, inlaid marble, and stuccos, a beautiful example of the western Roman architectural aesthetics. Galla Placidia, the daughter of emperor Theodosius the Great, commissioned the building after becoming an empress.

Located in ancient Ephesus in western Turkey, the Library of Celsus was built in 2 A.D. and held over 12,000 scrolls. Unfortunately, nowadays only its elaborate façade is left, though it is incredibly impressive. The multi-level structure was cleverly designed with relief carvings, Corinthian columns, and recessed false windows that made the structure look bigger.

The Arch of Septimius Severus is one of the most impressive buildings in the Roman Forum and was erected in 203 A.D. The structure commemorates emperor Septimius Severus’ victories in two Parthian wars and also honors his two sons, Caracalla and Geta (one of the central reliefs show the emperor shaking hands with them).

The city of Bath, called Aquae Sulis during Roman times, was a small town in the Roman province of Britannia known for its hot mineral springs—the only ones in England. The Romans built a bathing complex there that took several centuries to complete and was constructed as part of a temple.

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Another major Roman landmark in the French southern city of Nîmes is the grand amphitheater that was built shortly after the Colosseum. It has a perfectly oval shape and was designed so all of its 24,000 spectators had an unrestricted view of the arena. Just like the Colosseum, there were multiple galleries underneath where gladiators and animals were held before emerging on the arena through a series of trap doors.

Located at the heart of the Croatian city of Split, the magnificent Diocletian’s Palace was essentially the retirement residence of emperor Diocletian, who abdicated his position in 305 A.D. and moved here. It is the best-preserved ancient Roman palace in the world and also served as a Roman military camp.

Built under the patronage of consul Vipsanius Agrippa, between 16 and 15 B.C., this amphitheater could accommodate up to 6,000 spectators. They were seated according to social class from bottom to top, and each section was separated from the next one with barriers and a corridor. Behind the scene was a richly decorated 30-foot wall that featured two-level colonnades and statues of gods and emperors.

One of the cultural highlights of Amman (the city was called Philadelphia in antiquity) is this ancient Roman theater built in 2 A.D. by emperor Antoninus Pius. The structure was built on the side of a hill and had perfect acoustics that enabled even those sitting at the very top to hear what the actors on stage were saying.

This Roman gate has become a symbol of the German city of Trier.  It was an important Roman colony and a trading center at the beginning of 2 A.D. and was nicknamed “Rome of the North.” The city gate was built during the reign of Marcus Aurelius using grey sandstone (hence its name that translates into “black gate”). Even though it was erected as a fortress, it has palatial architectural features and is flanked by two towers.

This UNESCO World Heritage landmark is located in the heart of Évora, in central Portugal. It was built on a hill in the Corinthian order, and some believe it was dedicated to Diana, the goddess of hunting. In the 11th century, the temple was embedded in the walls of a medieval tower which may have actually saved it from destruction and looting.

The Roman Theatre of Orange, a UNESCO World Heritage Site, is one of the most impressive remnants of Roman architecture. Even Louis XIV described its façade as “the finest wall in my kingdom.” It was built on a hillside that made it easier to construct the terraced seating. The theater even had a removable canvas canopy that protected the audience from the elements.

While Pompeii’s demise was a tragic one, it also helped preserve the ancient city’s unique architecture under layers of ash. The houses were decorated with beautiful frescoes, stucco moldings, and fountains. The city also had an amphitheater that is the oldest surviving Roman amphitheater built around 70 B.C.