Emissarium of Lake Nemi

The Emissarium of Lake Nemi is an underground waterway that connects the lake to the Ariccia crater, running beneath the surrounding landscape. This ancient engineering work demonstrates Roman skill in managing water through solid rock.

Romans constructed this underground system around 2300 years ago to control water levels in the lake and prevent flooding. The work created additional usable land along the shoreline as a result.

The tunnel system demonstrates Roman architectural techniques through its opus quadratum blocks and specialized filtering mechanisms to maintain water flow.

The best way to explore this site is from the archaeological area near the lake, where entrance points can be seen and accessed. It helps to wear comfortable shoes and visit early in the day when fewer visitors are around.

The emissary tunnel incorporates multiple inspection shafts and maintenance access points, revealing Roman knowledge of hydraulic engineering principles.

Location: Genzano di Roma

GPS coordinates: 41.71293,12.69035

Latest update: December 14, 2025 16:43