On April 14, 91³Ô¹Ï's toughest students (8 females and 1 male) followed Professor Jens Koehler on a study and research trip to Lake Nemi, a volcanic crater lake in the Alban hills just 20 miles south-east of Rome. The aim was to explore an ancient emissary: a 1,683-meter-long tunnel, constructed to drain the high water of Lake Nemi into the next valley.
After only a few steps into the dark, narrow, low tunnel everybody understood why it was necessary to carry a helmet and a flashlight. The real fun started after half a mile (800 meters), where cold spring water floods the second, lower part of the tunnel.
Due to the rainy winter, the water was deeper than expected, reaching up to 3 feet (half a meter). Too much for tennis shoes, but equally too high for the professor's boots and even the rubber boots of the guide, Riccardo. What a relief to see the (sun)light at the end of the tunnel! After a short break the whole group returned, this time much faster, through water, rocks, and darkness back to Lake Nemi.
Understanding the Lake Nemi emissary formed part of the course "Roman Technology." The Romans were masters of hydraulics and built channels -- or emissaries -- to drain water from lakes Trasimeno, Albano and Nemi. Some of these emissaries can still be seen today, either above or below ground. The most interesting -- like that of Lake Nemi -- are underground and were used to siphon water away from lakes surrounded by hills.