ALBANUS PROJECT: INSIDE THE OLD EMISSARY

A documentary by MASSIMO D'ALESSANDRO

An ancient tunnel 1,420 meters long runs beneath Castel Gandolfo. A group of speleologists is attempting to traverse it, braving water, mud, gas, and submerged passages. Every obstacle they overcome brings the team closer to a mystery that has remained unsolved for centuries.

An ancient tunnel runs through the hill of Castel Gandolfo, on the outskirts of Rome. Beneath the landscape of the Alban Hills lies a structure that for centuries has governed the relationship between humans and water. It is the Emissary of Lake Albano, a tunnel carved into the rock for 1,420 meters between the lake and the village of Le Mole. Tradition links its construction to the war between Rome and Veii, to an inexplicable rise in water levels, and to a prophecy from the Oracle of Delphi. Even today, the tunnel retains traces of ancient excavation techniques. But for a long time, no one had managed to traverse its entire length.

The Albanus Project

In 2013, speleologists from the Hypogea Federation decided to tackle the exploration systematically. Thus was born the Albanus Project, a research program dedicated to documenting, studying, and highlighting the ancient emissary. The goal seemed simple: to traverse the tunnel from Lake Albano to Le Mole. The reality proved to be very different. Water, mud, gas, debris, cave-ins, and completely submerged passages turned every step forward into a technical challenge. An engineering feat that remains a mystery. The monumental entrance on the lake, called an "incile," leads to a channel carved beneath a hill hundreds of meters high. Through a system of filters and floodgates, the water could be regulated and channeled toward the fields and mills downstream. The entire structure operated by gravity, without pumps or external power sources. But during the initial explorations, an unexpected phenomenon emerged. Water continues to flow inside the tunnel, even though the lake's level is now much lower than the original entrance. Where is it coming from?

The first attempt to enter

The speleologists enter from the lake side. For the first few meters, the tunnel seems passable, but further on, the ceiling drops and meets the water. On the bottom lies a thick layer of semi-liquid mud. The divers' movements release gases produced by the decomposition of organic matter. To proceed, it is necessary to use cave diving techniques and equipment capable of completely isolating the diver from the environment. The attempt is prepared with great care. But what lies beyond the flooded section forces the team to rethink every plan.

Entering from the Other Side

After failing to gain access from the lake, the group reaches the outlet of the drainage channel in the Le Mole area. Here, too, the passage is blocked by trash, soil, and materials that have accumulated over the decades. The teams begin a lengthy process of clearing the area and searching for intermediate shafts. Each opening could provide a new access point to the conduit. However, every obstruction removed risks altering the delicate balance of the groundwater. The tunnel seems to react to their interventions, sending back unexpected signals.

A Race Against Obstacles

The documentary chronicles years of exploration, attempts, and reevaluations. The speleologists advance through narrow passages, navigate submerged sections, and navigate limestone formations that have built up over the centuries. Some parts of the outlet appear perfectly preserved. Others show collapses, widenings, and accumulations of material that block their progress. The further the team advances, the more evident it becomes that the tunnel is not merely an archaeological site. It is a system that is still active, connected to the waters flowing through the hill.

The Subsoil as an Environmental Archive

Much more recent traces can also be found inside the conduit. Waste and plastics that entered from the lake decades ago have remained almost intact in the darkness. These materials demonstrate how pollution can reach seemingly isolated underground environments. The exploration of the Albano Emissary thus also becomes a reflection on the fragility of water resources and the need to protect what is not visible from the surface.

From Piranesi to Contemporary Explorers

The Emissary has fascinated scholars and travelers for centuries. In the 18th century, Giovanni Battista Piranesi described it and depicted it in detailed technical drawings. In the 19th century, it became one of the attractions visited during the Grand Tour and was also mentioned by the Roman poet Giuseppe Gioachino Belli. The Albanus Project continues this long history of exploration, using modern technologies to answer questions that have remained unresolved for generations.

Will they manage to reach the entrance?

After years of work, the team manages to traverse most of the tunnel. But the final stretch remains blocked by one of the most difficult obstacles. To overcome it, new technical solutions, permits, and a complex sediment removal operation are needed. Just when the team seems close to a breakthrough, a new development once again changes the conditions of the exploration. The documentary takes the viewer to the very limit reached by the speleologists, leaving open the question that drives the entire project: will it be possible to traverse the ancient outlet completely?

AWARDS:

• BEST FEATURE DOCUMENTARY at the 2021 New York Movie Awards
• BEST FOREIGN DIRECTOR at the 2021 Roshani International Film Festival (India)
• SILVER AWARD FOR BEST FEATURE DOCUMENTARY at the 2021 Hollywood Gold Awards
• 3rd Jury Award at the "7th International Documentary Film Festival of Ierapetra & Awards" 2020
• Third place at the "9th Festival of Documentary and Archaeological Communication" in
Licodia Eubea (CT) 2019

FESTIVALS AND SCREENINGS:

• Official Selection, FLICKFAIR On Demand Film Festival 2022
• Official Selection, ESPELEOCINE 2021 – Mondonedo (Spain)
• Official Selection, BIDASOA Archaeological Film Festival (FICAB) 2021
• Official Selection, ARCHEOFILM Florence 2021
• Official Selection, SPELEOKAMARATON 2021
• Official Selection, 4th CYPRUS Archaeological Film Festival 2021
• Official Selection, Mediterranean Film Festival, Cannes 2020

INTERVIEWS:

CREDITS:

• Title: THE ALBANUS PROJECT: INSIDE THE ANCIENT EMISSARY
• Author: Massimo D'Alessandro
• Produced by: HYPOGEA and A.S.S.O. (Archeologia Subacquea Speleologia Organizzazione) ETS
• Scientific consultants: Carlo Germani, Carla Galeazzi, Vittoria Caloi
• Executive producer: Mario Mazzoli
• Cinematography: Stefano Barbaresi, Marco Vitelli
• Aerial footage: Francesco Marsala
• Narrators: Marta Altinier, Alberto Bognanni, Mimmo Strati
• Music: Edizioni Flipper Music
• Editing and Direction: Massimo D'Alessandro
• Running time: 53 minutes
• Language: Italian
• Subtitles: English
• 2019
• Genre: archaeological, speleological, and scientific documentary
• Themes: ancient hydraulic engineering, speleology, underground archaeology, water, environment
• Main locations: Lake Albano, Castel Gandolfo, Alban Hills, Le Mole