Temple of Olympian Zeus, Agrigento

Listen to the ground first. Under your shoes there is dry, crumbling earth, and all around you lie huge blocks of honey-coloured stone. They are scattered across the field and half-buried in grass and wild fennel. Lizards run across the warm surfaces. The wind comes up from the sea, and somewhere nearby the cicadas keep a steady hum. This does not look like a temple. It looks like the aftermath of something enormous. That is exactly what it is.

You are standing among the ruins of the Temple of Olympian Zeus. The Greeks called it the Olympieion. It was the most ambitious building ever attempted in the ancient city of Akragas, the Greek name for Agrigento. It was also one of the largest Doric temples the Greek world ever tried to build. Doric is the plainest and heaviest of the classical styles, with thick columns and simple, cushion-shaped capitals. Here, the builders pushed that style to an extreme scale.

To understand why, go back to the early fifth century before Christ. Akragas was a young and very wealthy colony, founded by Greek settlers from the nearby city of Gela. In 480 BCE, its ruler Theron joined forces with Gelon of Syracuse. Together they defeated a large Carthaginian army at Himera, on the north coast of Sicily. Carthage was the great Phoenician power across the sea in North Africa. The victory was a turning point for Greek Sicily, and Akragas wanted the gods to see its gratitude.

Ancient writers say the city used its prisoners of war as labour. According to the historian Diodorus Siculus, a Sicilian Greek who wrote centuries later, Akragas held so many captives that some private citizens owned hundreds of them. Many were sent to the quarries and building sites. So when you look at these blocks, consider the hands that cut them. The temple honoured a victory, but it was raised in part by the defeated.

Now look at the plan of the building on the ground. It covers an area more than one hundred metres long, about the size of a modern football pitch. Most Greek temples had a ring of free-standing columns around a central room. This one was different. Its outer columns were not free-standing at all. They were half-columns, built into a continuous stone wall. Between them, the walls were closed. The temple was a massive, enclosed box of stone.

Why build it this way? The likely answer is engineering. The architects wanted columns so wide and so tall that no single stone beam could span the gap between them. A solid wall helped carry the weight. Diodorus claimed that a grown man could stand inside one of the vertical grooves, the flutes, of a column. Look around for fragments of fluted drums. Measure one groove with your own body, and decide whether the old story holds up.

Here is the detail that makes this temple unlike any other. High on the outer walls, between the half-columns, stood giant stone figures of men. They are called telamons, or atlantes. Each one held up the heavy upper part of the building with bent arms raised above the head. Think of the myth of Atlas, the Titan who carried the sky on his shoulders. These figures were taller than a two-storey house, assembled from many separate blocks.

You can see one of these giants close by. A reconstructed telamon lies flat on its back among the ruins. On site, it is a copy. The original, rebuilt from its surviving pieces, stands inside the city's regional archaeological museum, a short walk up the road. Lying in the grass, the figure gives you a real sense of scale. Stand at its feet and look along its body toward the head. Then imagine dozens of them, high above you, in a row.

And now the first surprise. This temple was almost certainly never finished. Work went on for decades. In 406 BCE, Carthage returned and sacked Akragas, and the great project seems to have stopped. Ancient sources describe the building as still lacking its roof at that time. So the largest temple in the city may never have held a single complete ceremony under a finished ceiling. It was a promise that history interrupted.

The second surprise concerns what happened next. Earthquakes brought much of the structure down over the centuries. But people did the rest. For generations, the fallen blocks served as a ready-made quarry. In the eighteenth century, large amounts of this stone were carted away to build the harbour jetty at nearby Porto Empedocle. Part of the god's house is now down by the sea, holding back the waves, far from where you stand.

Look closely at the surviving blocks. Many of them carry deep U-shaped grooves cut into their sides. These were not decoration. Builders looped ropes through these channels and lifted the stones with cranes and pulleys. You can also see the rough local stone itself. It is a soft, porous limestone, full of tiny shells and holes. In ancient times, it was covered with a smooth coat of white plaster. Today, the bare stone glows gold in the late sun.

The giants never fully left the town's memory. Locals have long called the telamon simply the Giant. Three giants also appear on the coat of arms of Agrigento, a link many people here connect with this temple. So even after the walls fell, the figures stayed in the identity of the city. When you walk back through the modern town on the hill, keep an eye out for that emblem on buildings and signs.

Before you leave, stand still for a moment. Look east along the ridge, toward the other temples of the valley, which still keep their columns. Then look back at this field of broken stone. This temple did not survive as well as its neighbours. But it shows you something the complete ones cannot: the sheer ambition of a city that tried to build bigger than anyone before. Listen again to the wind and the cicadas, and walk on slowly.