The Pantheon's dome is still the largest unreinforced concrete one
Rome's Pantheon features the world's largest unreinforced concrete dome, a 2,000-year-old marvel of Roman engineering that still stands strong.
Built nearly 2,000 years ago, Rome's Pantheon boasts the world's largest unreinforced concrete dome, spanning an impressive 43.3 meters. This architectural marvel, completed around 126 AD, showcases Roman ingenuity in concrete technology. They achieved this by using a special mix of volcanic ash and varying the concrete's density, making it lighter towards the top. This clever design, along with the central oculus, allowed the dome to stand without internal supports or modern steel reinforcement. Its enduring stability, despite centuries of earthquakes, continues to inspire architects today.