Buzz
The architectural wonders and artifacts left by ancient civilizations have captivated historians and enthusiasts for centuries. From the awe-inspiring Parthenon to the iconic Great Pyramid, there seems to be an endless wealth of knowledge to uncover. However, what often lies beneath the earth’s surface far exceeds the marvels visible above ground. Hidden beneath our feet are ancient reservoirs, theaters, temples, and concealed fortresses — colossal underground constructions that remain a testament to the brilliant engineering of the ancient world.
10. Chavin De Huàntar, Peru
The pre-Columbian pilgrimage site of Chavin de Huàntar spans approximately 12,000 square meters (130,000 sq ft). Featuring artificial terraces, open spaces, stone structures, and a sunken plaza, its remarkable design emphasizes the site's significance in the ancient Andean religious realm.
The true heart of the site, however, lies in its network of three levels of underground tunnels, ventilation shafts, chambers, and stone-paved corridors. Here, visitors can observe engraved obelisks and sculptures left in place, and marvel at the grandeur of the site's masonry. Notably, the extensive system of drains and vents deep within the site stands unmatched in any other subterranean archaeological locations across South America, making Chavin de Huàntar one of a kind.
9. Qanat Firaun, Jordan
The Qanat Firaun, also known as the Gadara Aqueduct, was an ancient water system that provided vital supplies to the Roman-Hellenistic cities of Adraa, Abila, and Gadara. Rediscovered in 2004, this 170-kilometer (105.6 mi) pipeline is not only the longest underground aqueduct from antiquity but also one of the most intricate.
The aqueduct was built using the traditional qanat method, featuring vertical shafts every 20 to 200 meters (65–650 ft) connected by an array of tunnels. Hundreds of miners spent over 120 years completing this massive structure, excavating over 600,000 cubic meters (21,200,000 cu ft) of limestone, which is roughly equivalent to a quarter of the Great Pyramid’s total volume.
8. The Mithraeum at the Baths of Caracalla, Rome, Italy
Mithraeums were subterranean temples dedicated to the Roman Mithraic cult, which centered around the Persian god Mithra. During excavations at the Baths of Caracalla in 1912, archaeologists uncovered the largest Mithraeum known to date, spanning an area of 230 square meters (2,475 sq ft).
Sadly, much of the artwork in the grand hall has been lost over time, but several relief carvings and inscriptions have survived. One of the most notable remaining features is the fossa sanguinis, a deep pit into which initiates were lowered to undergo a ritual baptism in the blood of a sacrificed bull.
7. The Knights’ Halls, Acre, Israel
The Knights’ Halls were constructed by the Hospitaller Knights, a monastic order dedicated to caring for the wounded and sick during the First Crusade. Ingeniously built beneath the castle and prison of Acre, the port city that served as the gateway to the Holy Land, this complex of halls forms an integral part of the Hospitaller citadel.
The site comprises a dungeon, a historic Gothic church, several interconnected halls, and a dining area. Although the structure was largely destroyed by Muslim forces following the Crusaders’ defeat in 1187, it was reconstructed during the Second Crusade. Spanning three floors, only 5,000 square meters (53,819 sq ft) of this archaeological marvel has been uncovered so far.
6. The Basilica di San Clemente, Rome, Italy
From the exterior, the modest Basilica dedicated to Pope St. Clement, built in A.D. 99, may appear unremarkable. However, upon closer examination, it reveals itself as an unembellished, multi-layered reflection of Rome's religious history. Just beneath the beautifully adorned 12th-century Basilica lies the lower church, or lower Basilica, which dates back to the 4th century. This church was partially constructed over what is believed to have been the residence of a Roman nobleman.
In addition to hosting the papal conclave in 1099, the Basilica also houses one of the largest collections of early medieval frescoes in Rome. Beneath the lower Basilica, the remains of a building destroyed by the catastrophic fire of A.D. 64 can be found, along with a Mithraeum that contains several monuments used by the Mithraic cult.
5. Prasanna Virupaksha Temple, Hampi, India
Amid the mesmerizing ruins of Hampi, a World Heritage Site, the Prasanna Virupaksha Temple—also known as the Underground Shiva Temple—lay buried for over 400 years before it was rediscovered in the 1980s. Believed to have been used by the royal household during private ceremonies, the temple is similar in design and layout to the temples located on Hermakuta Hill, and features a variety of carvings, sculptures, and murals.
The grand inner sanctum includes an impressive pillared hall and beautifully carved columns that actually extend through the roof. The floors of the hall—as well as the inner sanctum—remain underwater despite excavations and ongoing attempts to preserve the site.
4. Hal Saflieni Hypogeum Island Of Malta
The Hal Saflieni Hypogeum dates back to around 2500 B.C., making it the only known prehistoric subterranean structure in the world. Although many believe it started out as a sanctuary, it also served as a necropolis, and thousands of human remains have been located within its mysterious chambers. One of its most significant features is the Oracle Room—a carved hole in the wall which produces an echo that reverberates throughout the Hypogeum whenever someone speaks into it.
Several smaller chambers spread across the three levels capture these echoes and transform the reverberations into a sound resembling a heartbeat, leading many to believe the hole played a significant role in ancient ceremonies. Other remarkable features include its unique alignment with the equinoctial sun, large carved stone structures similar to those at Stonehenge and Baalbek, and an intricately painted ceiling adorned with ocher spirals.
3. The Basilica Cistern, Istanbul, Turkey
The name Basilica Cistern might suggest it was merely an ancient water reservoir, but in reality, it is far more fascinating. In the third and fourth centuries, a grand temple surrounded by beautiful gardens stood in its place. After it was destroyed by fire, Emperor Justinian ordered 7,000 slaves to rebuild the structure on the same site, covering an area of 9,800 square meters (105,500 sq ft). Also known as the Sunken Palace, it is a truly awe-inspiring sight.
The Cistern’s vaulted ceiling rests on 336 engraved marble columns, each standing 9 meters (30 ft) tall. To enter, one must descend a set of stone stairs. When operational, the Cistern provided water to structures on the First Hill, including the Great Palace of Constantinople, and continued to serve its purpose into modern times. Today, only a small amount of water remains. It has been featured in several films, novels, and more recently, a video game.
2. Tomb of Seti I, Abydos, Egypt
The Tomb of Seti I holds the distinction of being the longest and deepest of all the tombs in Egypt's Valley of the Kings. It was the first to be richly decorated with intricate reliefs, colorful frescoes, and a finely carved column depicting Seti I alongside the goddess Hathor. Every chamber, ceiling, and passage was adorned with art, setting the standard for the tombs of future kings. However, due to excavations in the 1950s and 60s that altered the tomb's moisture balance, many walls have cracked or collapsed, and it is now largely closed to the public.
1. Mausoleum of Qin Shi Huang, Xi’an, China
The Qin Shi Huang Mausoleum, a 2,200-year-old burial site, is the final resting place of China’s first Qin emperor. Although most famous for its partially excavated terracotta army flanking the mound to the north and south, the mausoleum is actually China’s most lavish tomb complex. Comprising four layers, it features an underground palace, an inner city, an outer city, and a range of subordinate buildings and tombs.
Spanning over 600 square meters (6,500 sq ft), the underground site took over 700,000 laborers more than 38 years to construct. Despite decades of excavation, archaeologists have barely begun to explore it fully. The central tomb, which houses the underground palace, remains untouched, but ancient records suggest it was designed to mirror the emperor’s actual palace, occupying more than two-thirds of the inner city.
