Our Top 10 Ancient Engineering Projects Still in Use

From water systems to roads and bridges, ancient civilisations were solving infrastructure challenges thousands of years ago, often with nothing more than basic tools, clever design and a deep understanding of their environment.

What's even more impressive? Some of these assets are still in use today. Here are our top 10 ancient engineering projects that have well and truly stood the test of time.

1. The Cornalvo Dam, Spain

Built in the 1st–2nd century CE, this Roman dam still supplies water to Mérida. A mix of earth and masonry construction, it’s a testament to early hydraulic engineering done right.

2. Pons Fabricius, Italy

Built in 62 BCE, this is the oldest surviving bridge in Rome still in use. Despite floods and repairs over the centuries, it continues to carry foot traffic across the Tiber.

3. Byblos Port, Lebanon

Established around 6500 BCE, Byblos evolved into a major Mediterranean port by 3000 BCE. It remains active today, making it one of the longest continually used ports in the world.

4. The Appian Way, Italy

Constructed in 312 BCE, this Roman road connected Rome to Brindisi. Its layered design and drainage camber set the standard for road construction, and some sections are still walkable today.

5. The Arkadiko Bridge, Greece

Built between 1300–1190 BCE, this Mycenaean bridge is still crossable. Designed for chariots, its stone arch has held up for over 3,000 years.

6. Cloaca Maxima, Italy

Dating to around 600 BCE, this massive drainage system helped transform Rome from marshland into a functioning city. Parts of it still operate as a stormwater system.

7. The Gonabad Qanat water management system, Iran

Built between 700–500 BCE, this underground system stretches over 30 km, using gravity to transport water. It’s still supplying water in one of the driest regions on earth.

8. The Furlo Pass Tunnel, Italy

Constructed between 69–79 CE, this tunnel carved through solid rock is still in use today, now carrying modern road traffic.

9. Tower of Hercules, Spain

Built in the 1st century CE and still operational, this 55m Roman lighthouse has guided ships for nearly 2,000 years.

10. Proserpina Dam, Spain

Also built in the 1st–2nd century CE, this gravity dam continues to hold water today, highlighting the longevity of Roman infrastructure.

These projects are proof that good design lasts. Long before modern machinery, engineers were building for durability, resilience and long-term use.

For today’s infrastructure industry, it’s a reminder that while technology has evolved, the fundamentals haven’t changed. Get the design right, and your work might just outlast you by a few thousand years.