The Roman Amphitheater
Beneath the bustling streets of London lies an ancient structure that predates much of what is visible today. The Roman Amphitheater, discovered in 1988 during archaeological excavations beneath a parking lot near the Guildhall in the City of London, provides a unique glimpse into the city’s past. This amphitheater was part of Londinium, the Roman settlement established in AD 43, and it served as an entertainment venue for the Romans who inhabited the area.
The amphitheater could seat around ten thousand spectators, making it one of the largest such structures in Roman Britain. It was used primarily for gladiatorial combats, animal hunts, and public executions. The arena itself was surrounded by a wooden or stone seating structure, with entrances that allowed spectators to enter and exit through different gates. This elaborate design reflects the sophistication of Roman engineering and city planning. Excavations have revealed parts of the retaining wall and traces of the wooden seating structures, offering insights into how these events were staged.
The preservation efforts for this site are remarkable, given its fragile condition underground. The City of London Archaeological Archive houses artifacts found during excavations, including items like pottery, weapons, and tools used in daily life by the Romans. These artifacts not only paint a picture of Roman Londinium but also serve as educational resources for understanding the culture and daily lives of ancient Romans. Visitors can explore this area through guided tours that provide context to the ruins and highlight the ongoing archaeological work.
The London Mithraeum
Deep beneath modern office buildings in the heart of London’s financial district lies a hidden gem: the London Mithraeum. This subterranean temple, dedicated to the Roman god Mithras, was unearthed during construction works in 1954 and later re-excavated in 2017 after it had been relocated for safety reasons. The site’s discovery has provided valuable insights into the religious practices of Roman Londoners.
The Mithraeum, named after its dedication to the god Mithras, was a place where initiates of the mystery cult would gather for secret rituals and rites. This underground temple features an altar, niches for statues, and elaborate frescoes that depict scenes from Mithraic mythology. The architectural details suggest that it was designed with precision, reflecting the meticulous approach to religious spaces in Roman times. These intricate carvings and murals were likely painted on plaster walls and have since been meticulously restored.
The London Mithraeum is not just a historical site; it also serves as an educational resource for understanding the cultural and religious landscape of ancient Rome. Visitors can explore the temple’s interior, where they will find artifacts such as statues, votive offerings, and inscriptions that provide clues about the cult’s practices. The museum’s exhibits offer context to these artifacts, explaining their significance in the broader Roman religious framework. Additionally, guided tours are available, offering visitors a chance to learn more about the excavation process and the ongoing preservation efforts.
WWII Air-Raid Shelters
Beneath London’s streets, remnants of World War II air-raid shelters offer a poignant reminder of the city’s resilience during times of conflict. These underground structures were built as protection for civilians from German bombings during the Blitz, a period marked by intense aerial attacks on British cities.
The most notable of these is the Churchill War Rooms, located in Westminster. This network of tunnels and rooms served as the command center for Winston Churchill’s government throughout World War II. The preserved rooms include offices, meeting spaces, and sleeping quarters, all designed to support the continuous operation of the war effort from within the safety of the underground complex. Visitors can explore these chambers, which are still filled with original furnishings, documents, and personal items belonging to key figures of that era.
Another lesser-known but equally fascinating site is the Clapham South deep shelter, one of several shelters built in London during the Blitz. These shelters were equipped with amenities like beds, cots, and even a hospital for those who might be injured or ill. The Clapham South shelter could accommodate up to 8,000 people at once, providing not just safety but also a community space where residents could gather during times of crisis. Modern tours allow visitors to walk through the narrow corridors and rooms, imagining what it must have been like for Londoners seeking refuge during air raids.
These air-raid shelters are more than just historical sites; they serve as memorials to the perseverance of Londoners during one of the darkest periods in British history. They also provide a unique opportunity for visitors to understand the day-to-day realities faced by civilians during the war. Guided tours often include stories from survivors and historians, adding a human element to the exploration of these underground spaces.

The Victorian Sewer System
Beneath London’s modern infrastructure lies an intricate network of sewers that were constructed during the Victorian era. These tunnels, designed by engineer Joseph Bazalgette in the mid-19th century, not only revolutionized sanitation in London but also offer a fascinating glimpse into the engineering prowess of the time.
The sewers were built to address the serious public health issues caused by poor sanitation and the frequent outbreaks of cholera. By diverting raw sewage away from populated areas and directing it towards treatment plants, Bazalgette’s system significantly reduced the spread of waterborne diseases. This project required extensive construction efforts, including digging deep into the ground to lay large underground tunnels.
Visitors can explore parts of this vast sewer network through guided tours offered by London Sewer Tours. These tours provide a unique opportunity to see firsthand the scale and complexity of these underground structures. Tour guides often highlight key points of interest, such as ventilation shafts that were ingeniously designed to maintain air circulation throughout the tunnels. Participants also learn about the daily lives of sewer workers who maintained these systems during Victorian times.
The sewers have had a lasting impact on London’s urban development and public health. They exemplify how engineering solutions can address major societal challenges, setting a precedent for modern sanitation systems worldwide. The tours offer not only an educational experience but also a deeper appreciation for the hidden infrastructure that keeps cities functioning efficiently.

Roman Fortifications
Beneath certain parts of London lie remnants of the Roman fortifications that once protected the city during its early years as Londinium. These structures, though partially obscured by centuries of urban development, offer valuable insights into the defensive strategies and daily lives of ancient Romans in Britain.
One such site is located near the Barbican Centre, where excavations have uncovered parts of a Roman fortification wall. This section provides evidence of how the city was defended against potential invaders. The walls were constructed using large blocks of stone and were reinforced with timber structures to enhance their stability. These defensive measures reflect the strategic importance Londinium held during the Roman occupation.
Excavated artifacts from these sites include pottery, coins, and tools that help historians piece together the daily lives of Romans living within the fortifications. The presence of military equipment, such as helmets and shields, indicates that soldiers were stationed here to ensure the safety and security of the settlement. Archaeologists have also found evidence of marketplaces and residential areas near these walls, suggesting a thriving urban community supported by robust defense mechanisms.
Guided tours are available for those interested in exploring these underground fortifications. Tour guides provide historical context about Londinium’s strategic significance and how it evolved over time. Visitors can walk through reconstructed sections of the wall and imagine life within this fortified city, gaining a deeper understanding of the Roman presence in Britain and its lasting impact on London’s urban development.