When we think of the wonders of the ancient world, images of the Egyptian pyramids, the Lighthouse of Alexandria, or the Colossus of Rhodes often come to mind. Yet, there were many other astonishing feats of engineering crafted in ancient Greece by our ancestors—achievements that, over time, have largely faded into obscurity.
Acrocorinth: The Star of Stars
From the moment a small settlement named Ephyra was founded near the towering rock of Acrocorinth—a village that would later grow into the wealthy and proud city of Corinth—this natural fortress has been a symbol of the city’s existence. According to korinthos.gr, Acrocorinth was fortified with exemplary skill, making it the most significant defensive structure in the region from antiquity to modern times.
Serving as Corinth’s acropolis, Acrocorinth (from “akro” meaning “high” and “Corinth”) was crowned with mighty fortifications. Originally built during the Mycenaean era, it achieved monumental grandeur in the 7th and 6th centuries BCE under the rule of the Cypselid dynasty, which brought Corinth to its peak prosperity. With its 574-meter elevation and strategic position, the fortress withstood every attempt at conquest and earned the nickname “The Star of Stars.” Today, it stands as the largest castle in Greece, and one of the largest in Europe.
In antiquity, the site was also home to the famed Temple of Armed Aphrodite, where priestesses engaged in sacred prostitution. The Greek geographer Strabo, writing in the early 1st century CE, noted that the temple was served by nearly a thousand hierodules—sacred prostitutes dedicated to the goddess of love. These women, offered to the temple by men and women alike, took part in sexual rituals with visitors as a form of religious devotion.
The Colossus of Naxos
At the ancient marble quarry of Apollonas on the island of Naxos lies a colossal, unfinished statue known as the Kouros of Apollonas—an awe-inspiring sight. Believed to date back to the 6th century BCE, the kouros is over 10 meters long. Scholars remain divided over whether it was meant to depict the god Apollo or Dionysus.
Intriguingly, construction of the massive Temple of Apollo at nearby Portara began during the same period, prompting speculation about whether the statue was connected to the sanctuary.
The kouros was never completed—possibly because it cracked and was deemed irreparable, or perhaps due to the cancellation or non-payment of the commission.
Eupalinos Tunnel – Samos
The Tunnel of Eupalinos, carved into the island of Samos in the 6th century BCE, is one of the most remarkable achievements of ancient engineering. Built to supply water to the capital city under the rule of tyrant Polycrates, the tunnel carried fresh water from springs located on the far side of Mount Kastri.
Greek historian Herodotus credited the project to Eupalinos of Megara, an ingenious engineer. According to the Encyclopedia Britannica, the tunnel—over 914 meters (3,000 feet) long and about 2 meters wide—was dug straight through solid rock by teams of slaves using only hammers and chisels.
The aqueduct remained in operation for more than 1,000 years, and today, visitors can walk its full length—a rare opportunity to step inside the precision and ambition of ancient infrastructure.
The Paved Road of the Diolkos
A marvel of ancient Greek engineering, the Diolkos was a paved road designed to allow ships to be hauled across the narrow Isthmus of Corinth, enabling them to avoid the perilous and lengthy journey around the Peloponnese by sea.
As detailed by greekreporter.com, ships traveling eastward would arrive at the Diolkos’s northwestern end—modern-day Poseidonia in Corinth—where a stone ramp awaited. There, slaves would drag the vessels onto the ramp using giant ropes. Once ashore, the ships were stripped of their masts and other removable parts to reduce weight.
The massive vessels were then rotated 90 degrees using large winches operated by many men, aligning them with the Diolkos road. After being hoisted onto a heavy-duty wooden frame or sled mounted on metal wheels, the ships were pulled across the stone-paved route to the opposite coast.
The innovation is attributed to Periander, the second tyrant of Corinth (ca. 627–587 BCE), who fully exploited the city’s commercial and cultural potential. While he is often remembered as a harsh ruler, that reputation, according to Encyclopedia Britannica, likely stems from his fierce clashes with the Corinthian aristocracy.
Library of Pergamon
Founded in the city of Pergamon (in modern-day Turkey) by King Eumenes II of the Attalid dynasty (r. 197–159 BCE), the Library of Pergamon became one of the most esteemed centers of learning in the ancient world—second only to the legendary Library of Alexandria.
The Attalids, who rose from humble origins, embraced arts and letters as a way to establish themselves as a respected royal power. At its height, the library is said to have housed 200,000 volumes, most written on parchment. The growing demand for writing material from scholars visiting Pergamon led to increased parchment production in the city—so much so that the English word "parchment" derives from the Latin "pergamenum," referencing Pergamon.
According to worldhistory.org, the rivalry between the libraries of Pergamon and Alexandria triggered an intense race to collect as many texts as possible. Some scholars went so far as to hide their private collections to prevent them from being seized by King Eumenes, his brother Attalus II, or Egyptian Pharaohs Ptolemy V and Ptolemy VI.
After King Attalus III (r. 138–133 BCE) bequeathed Pergamon to the Roman Republic, the Romans continued to maintain the library, which remained active well into the Byzantine era.
These are just a few of the forgotten “wonders” of ancient Greece. While they may not be as widely recognized as their more famous counterparts, they undoubtedly deserve our admiration, attention, and thoughtful study. Their stories remind us that behind the ruins lie ingenious minds, daring feats, and civilizations that pushed the limits of their world.
