 The best-preserved Roman buildings exist throughout the sprawling Roman Empire. Today we'll travel all around the confines of the Empire, but we'll start first with Rome, which was the capital and had more buildings than any other city. It was the largest city in antiquity, up to 1 million inhabitants, and as the later people capital, so many of its buildings remained in use, thereby ensuring their preservation. Let's start with the Colosseum. It once held 50,000 spectators built by Vespasian between 70 and 80. It remained in use throughout antiquity, and then lived on as a fortification and a place of inhabitation in the Middle Ages, ultimately treated by the Catholic Church as a symbol of the martyrdom of Christians. We can appreciate the underbelly, the hippo-jam. This is where the animals waited in cages. This is where the gladiators waited to be hoisted up in elevators. It's got 300 years of modifications. And of course we can appreciate the full height of the monument, 50 meters. It truly is magnificent, and we get a full experience of the Colosseum when we look at it today. The pantheon was built between the reigns of Trajan and Hadrian, finished by about 125, and it's the best-preserved temple anywhere in the Roman Empire. We could admire the porch. We could admire the bronze doors. And of course the interior space is magnificent. The pavement is a copy of the original format, but the columns inside are still original as are the niches. And we pivot up to the concrete dome, the largest unreinforced concrete dome in the world with its original coffers still intact. And of course that interior space is like a perfect sphere inside a cylinder. And of course the rain still comes down through the best-preserved temple in the Roman world. We can pass over to the frigidarium space of the Baths of Diocletian, constructed at the end of the 3rd century AD. 50 meters by 22 meters with an original height of 30 meters. This cold hall was converted by Michelangelo into the Church of Centimony of Deliangeli. The markets of Trajan, built by Trajan between 107 and 110, is a administrative center or a shopping mall with 150 stalls. Maybe both. It is built on three separate terraces alongside the Quirinil Hill of Concrete and Brick. It feels modern, it feels like it was built yesterday. And of course inside of it there is a magnificent central hall possibly used for grain distribution. It is an incredible concrete poured vaulting system created by the Emperor Trajan. The Quiria, 31 meters in height, is the meeting hall for the Roman Senate. And what we see today is rebuilt after a fire of 283. But it is an exact copy of that of the time of Augustus. And we can peer inside of the late antiquity, opus sectule pavement and admire this interior space so well preserved because it was converted into a church in the 7th century dedicated to St. Hadrian and then ultimately de-consecrated in the 1930s. Passing into the Formboire and the cattle market, we look at the oldest preserved marble temple from ancient Rome, 2nd century BC. And it's so well preserved because it's converted into a church of St. Stefano of the Carriage Makers. But what we can admire is that pentallic marble imported from Greece and constructed by sculptors from Greece as well. Let's explore now the rest of the empire starting in North Africa. Let's head to ancient Thysdrus, to the city of Elgem. This was a city that became rich from caravan trade and olive oil exportation. And they built a magnificent amphitheater holding up to 35,000 spectators in the 3rd century, the second amphitheater of the city. It's massive and beautiful and golden in the sunlight. It's Africa's greatest amphitheater. It was later used as a quarry site and partially dismantled in the 17th century to prevent its use as a fort. But we can still explore today making our way up to the top tier, to the nosebleed seats, to admire this impressive amphitheater. Now let's head to Egypt and to the island of Philae, sacred to Isis. Egypt, conquered by Augustus, remained very popular under the Romans and several Roman era monuments were constructed including this, the so-called kiosk of Trajan built between 98 and 117. It's 15 by 20 meters in size, 15 and a half meters high. It was unfinished but seems to have been used as an offering, one of the sacred birth houses to Isis. And it has unique architectural features, innovative capitals, there was so much going on in Roman Egypt and this inscription here and these figures show the emperor Trajan making his offerings to the goddess Isis. It's a monument that we can explore today and admire the presence, the persistence of the Romans and their close ties and interest in the cult of Isis throughout the Roman Empire. Now let's travel to the desert of Jordan and to a Roman castrum. It's in an isolated location, 50 miles south of modern-day Amman, it's Khazir Bashir and so much of it has been preserved. The stones have not been robbed out because as in antiquity as today it's in a rather isolated location far from any urban development. It's 50 meters on a side, basically a square and it was a castrum used for surveillance with the Calvary unit of the Limitani up to 60 people with stables and barracks protecting this portion of the empire. The inscription dates the site to the reign of Diocletian and after debanement in late antiquity basically no one came back here and so we have just impressive remains of this castrum, one of the best preserved castrum structures from the entire Roman Empire. The towers are in place, the gates in place with the original inscription, it's still impressive today. It's not the biggest fort but it's on the edge of the Roman Empire guarding that border in caravan traffic. Now let's travel to Lebanon to the sanctuary of ancient Baalbek of Heliopolis, one of the greatest sanctuaries from the ancient world. And most of what we see today is of Roman date and truly the standout feature here is the so-called temple of Bacchus which is largely intact with its columns, coffers and interior cellar lined with columns truly extraordinary. We think constructed in the reign of Antonius Pius, it's 66 meters long, 35 meters wide and a full height of 31 meters is preserved. This sanctuary and this monument remained intact and well preserved but this site starts to get sacked from the 7th century and onward and raided over subsequent centuries. Now let's travel to Turkey to Istanbul, ancient Constantinople and the Hagia Sophia built by Justinian between 532 and 537. It's one of the greatest dome structures still standing. Now it suffered a lot of earthquake damage. In fact the original vault built by Justinian had to be rebuilt and today we see its interior height of over 55 meters. Later converted into a mosque in 1453 under Sultan Mehmed II thereby preserving this glorious monument, this amazing Roman building. Now let's travel to Greece and Athens and the Odeon, the music hall built in 161 by Herodes Atticus in memory of his wife Ania Regilia. That was used as a venue for music concerts, originally it was roofed over with a timber roof with a capacity for 5000 spectators and it was in use all the way until its destruction in 267. There's been some heavy restoration of the stage building, it's still in use for concerts today. Now let's travel to Diocletian's Palace in Croatia to the modern day city of Split. Justinian retired near his birthplace Solona and he built this fortified villa at the end of the 3rd century AD, a seaside residence and also included his mausoleum. And the thing is we have most of it still today as it became the core of the city of Split which was founded inside the remains in the 7th century. We have the walls largely intact, roughly 200 meters by 175 meters and the core of it, this vestibule right here is intact. Next to it the mausoleum of Diocletian later converted into the church of the local saint Domlius. So it's an impressive ruin that we can admire on multiple levels and of course we see right here in the center that changeover from the vestibule space of Diocletian into this impressive church of Domlius which was originally the mausoleum of the emperor Diocletian. And there's so much more in this site that we can admire including this temple of Jupiter intact on the exterior as well as the interior vaulting and the reason why we can admire so much of it is because it was converted into the baptistry for that local church of Domlius. It's an absolute miracle that we have so much, so many components of the Villa of Diocletian. Finally, let's travel to Germany to Trier, the ancient city of Augusta Trevororum, the western capital of the late empire. And here we have so much built in the reigns of Constantius Chlorus and Constantine the Great including this large hall built between 300 and 310. You're going to have a palace in the western capital, you're going to have a large hall and this one is of monster dimensions. It's like having two couriers from the Roman Forum, 67 meters long, a width of over 26 meters and a height of 33 meters. In the Middle Ages it became part of the Bishop of Trier's residence and ultimately we have it because it's been converted into a church. There you have it, some of the greatest Roman buildings from around the Roman Empire. We have many well preserved buildings and monuments to share in another video. Please watch our weekly videos on Ancient Rome and our live stream videos on countless topics on the history of Ancient Rome. Thanks for watching and subscribing.