Hierapolis

Listen to the ground for a moment. Gravel crunches under your shoes, dry and pale. Somewhere below the ridge, warm water runs over white stone. On a hot afternoon, the air carries a faint mineral smell, a little like chalk and a little like a spa. You are standing on a plateau above the Lycus valley in southwestern Turkey. Behind you lie the ruins of a city that was built here because of that water.

This is Hierapolis, the Holy City. Its name comes from Greek, and the holiness it refers to was tied to the earth itself. Hot springs rise here from deep underground. They carry dissolved calcium, and as the water cools in the open air, that calcium hardens into the white terraces of Pamukkale just below you. The ancient city and the natural terraces were listed together as a single UNESCO World Heritage Site in 1988.

The city as a planned Greek settlement is usually credited to the Attalid kings of Pergamon, a Hellenistic dynasty that ruled much of western Anatolia in the second century before Christ. Later, the region passed to Rome. Under Roman rule, Hierapolis grew into a prosperous spa town. People came to bathe, to heal, and to worship. Merchants came too, because the mineral water was used for dyeing wool, and the textiles of this valley had a strong reputation.

The ruins around you are mostly Roman, and there is a reason for that. In the year 60, during the reign of the emperor Nero, a severe earthquake struck the Lycus valley. Much of the earlier city fell. What you see today was largely rebuilt afterwards, in a confident imperial style. Earthquakes returned again and again over the following centuries. This is an active landscape. The same forces that heat the water also shake the ground.

Walk north along the main colonnaded street, and you reach the Frontinus Gate. It has three arches set between two round towers. The gate is named after Julius Frontinus, a Roman provincial governor, and it dates to the late first century. Beyond it, a wide paved road ran straight through the city. Stop and look down at the paving stones. In places you can still see worn grooves from cart wheels, cut by traffic nearly two thousand years ago.

Outside the gates stretches the necropolis, the city of the dead. It is one of the largest ancient cemeteries in Anatolia. There are simple stone sarcophagi, house-shaped tombs, and round burial mounds called tumuli. Many people who came here seeking a cure never left. Some sarcophagi are tilted or half buried, pushed out of place by earthquakes and by centuries of mineral deposits. Walking among them in the late light is quiet and strange. The tombs line the road like a long, broken street.

Here is a detail most visitors walk past. A sarcophagus found in this area, belonging to a man named Marcus Aurelius Ammianos, carries a carved relief of a water-powered stone saw. A water wheel drives a crank and a connecting rod, which push two saws back and forth through blocks of stone. Historians of technology treat it as the earliest known image of this kind of machine. It is from the third century. The original can be seen in the area, and it is easy to miss.

Now turn uphill toward the theatre. It is cut into the slope of the hillside and faces out over the valley. The structure you see was rebuilt in the Roman imperial period, and its stage building was decorated with carved marble friezes showing gods and myths. Climb a few rows and sit down. From the upper seats, the ruins, the white terraces, and the plain below all fit into one view. The audience in antiquity looked at much the same horizon.

Near the theatre lies a place that ancient writers described with fear. It is the Plutonium, the Gate of Pluto, named after the Roman god of the underworld. A small cave here released a heavy gas that killed birds and animals almost at once. Priests, it was said, could enter and come out unharmed. Italian archaeologists identified the site in 2013. Scientists later measured high levels of carbon dioxide pooling near the ground there, which helps to explain the old stories.

Hierapolis also holds an important place in early Christian history. Christian tradition says that Philip the Apostle died here as a martyr in the first century. On the hill to the northeast stands the Martyrium of Saint Philip, an eight-sided building constructed in his memory around the fifth century. Pilgrims came from far away to visit it. In 2011, the Italian team working at the site announced that they had found a tomb they believe belonged to the apostle, in a nearby church.

The city produced a famous thinker as well. The Stoic philosopher Epictetus was born here in the first century. He was born into slavery, and he later became a free man and a teacher in Rome and Greece. His central idea was simple and practical. Some things are within our control, and some are not. Peace comes from knowing the difference. It is a thought worth carrying through a city that earthquakes destroyed and people rebuilt many times.

Before you leave, look for the Antique Pool. It is a warm spring pool, and fallen marble columns lie on its floor under the clear water. They came down in an earthquake and were simply left where they fell. Swimmers float above them. Locals sometimes call it Cleopatra's Pool, and legend says the Egyptian queen bathed here. There is no historical evidence for that story, but it has followed the pool for a long time.

Nearby, the Hierapolis Archaeology Museum is housed inside the stone halls of a large Roman bath complex. The building itself is part of the exhibit. Its thick walls and high vaults keep the rooms cool even in summer. Inside are statues, sarcophagi, and reliefs taken from the theatre and the city. Many pieces came from the excavations around you. It is a good place to put faces and names to the empty streets you have just walked.

When you go down to the terraces, you will be asked to take off your shoes. The stone feels warm and slightly rough, with small ridges where water has left thin layers of mineral. Pause at the edge. Look back up at the ruins one more time. The water is still flowing, still leaving its thin white layers, just as it did when this was a living city. Every step you take on that stone sits on top of centuries of slow, quiet building.