Simple to construct, walls are easier to build than arcades, although walls can impede the natural flow of water and people. When engineers need to raise the aqueduct's channel more than ...

Built in the first century, the aqueduct of Segovia – now a UNESCO World Heritage Site alongside Segovia's historic centre – delivered mountain water to the city for almost 2,000 years.

Still in use to this day, the aqueduct carries water from the Frío River to the city of Segovia. The central section has two layers of arches that stand 28.5 metres (93.5 feet) above the ground.