THE FROZEN LAKE OF RAIBL

Raibl and Fusine

Let’s say it right away: all frozen lakes “sing”. Even small suburban ponds and artificial basins or peat bogs, as long as they’re deep enough for the surface to transform into a resonant plate when freezing. So the invitation is to take advantage of winter when temperatures drop sharply below zero to reach any of these places.

Lake Predil (Rabil in Friulian, Raibl in German, Rabelj in Slovenian) is something truly unique. It has a significant surface area – at 610,000 square meters, it’s the second largest in the region after Lake Cavazzo – and its position at almost 1,000 meters above sea level exposes it to harsh winter temperatures that can provide ideal conditions for this type of acoustic experience.

Thanks to the temperatures in this area, the two Fusine lakes also offer the same spectacle, but they are smaller, therefore less powerful, and much more frequented, so they may not offer the ideal silence conditions for listening.

A years-long hunt

The first time we happened to hear the sound of Lake Predil was by chance and we didn’t have recorders or microphones with us, but that experience certainly played a role in the genesis of the Topofonie project. It’s one of the most incredible and fascinating acoustic phenomena in the region, but it’s not easy to find. We constantly monitored weather forecasts with the certainty that at the first winter – these areas are renowned for their polar temperatures – we would bring home our acoustic trophy.
But it wasn’t like that.

In recent years, temperatures haven’t dropped low enough and long enough to allow the formation of the ice sheet. Moreover, although it’s a phenomenon known to local inhabitants (they say the lake “sings” or “cracks”), freezing is not a sufficient condition and it seems it’s not easy to predict exactly when it’s best to go listen to it. Generally, the rule of the early bird applies, because with sunrise the temperature rises and the ice begins to move. However, you should know that you might make a wasted trip, although the spectacle of the frozen lake, even if silent, is wonderful.

Howls, cracks and space lasers

The lake sings in many different ways, each more amazing than the last. Which one you can hear depends on the thickness of the ice, the presence of snow, sun and temperature trends, and naturally a bit of luck.

If the ice sheet on the surface is dry, extensive but still thin enough, then you can make it sound by hitting it with a stick from the shore, or throwing a fairly large stone on it. The sound it produces is something striking, similar to a laser in a science fiction film, with the power of the vastness of the basin and accompanied by the silence of this valley that acts as a natural amphitheater. This type of sound is the most difficult to find, because it requires rare weather conditions, involving the first sudden freeze and probably won’t repeat before a new winter or a new freezing process. We still haven’t managed to record it, but we’ll try again.

When instead the ice layer is thick enough that you can walk on it and is too rigid and heavy to be manually vibrated, then it will dictate the rhythm of its song – you just need to listen.

A lake in F sharp

The ice is alive, with varying temperatures it expands and contracts, generating deep howls that recall the calls of large cetaceans. The continuous and persistent sound that can be heard from any point in the valley probably varies according to the thickness of the ice and its extension. During the recordings we made in January 2026, the lake was “singing” around two specific frequencies, 138Hz and 180Hz. Musically speaking, you could talk about a drone with cadence in F#.

Sudden cracks often occur, which depending on the presence of snow on the surface generate more or less deep or muffled sounds. These sounds are accompanied by cascading echoes in rapid succession and flanger effects that make you think of ice as an elastic material.

For the cracks, a privileged listening point is directly on the lake, obviously when possible. The northeastern part, overlooking the Chalet, is the shallowest, often freezes completely so much that children go there to play to build igloos or to skate.
Standing directly on the ice, you can distinctly perceive the area where the cracks occur, whether they are closer or farther, larger or smaller, from which part of the lake they come. The spatiality is very evident. You might also feel them through your feet, which can give a slight sense of anxiety, but these are millimetric movements on surfaces hundreds of meters long.

If the acoustics are muffled by snow, cars traveling on the two roads on the sides of the lake provide a backdrop with white noise trails in stereo to the right and left. Both roads are very beautiful to travel at the end of the day. The SS54 leads to Slovenia via Predil Pass, while the SP76 leads to Sella Nevea, excellent for making a stop at the topophony of the Fontanone di Goriuda.

Suoni in estinzione

Frost is responsible for other interesting acoustic phenomena in this area. Some are destined to become extinct, if they haven’t already (see also the chapter dedicated to the Fontanone di Goriuda in Daniele’s story, manager of the restaurant below). The sound of frozen Lake Predil is certainly an experience worth having, before it’s too late.