by Alessandra Ressa
The rugged limestone landscape of the Karst Plateau has long concealed the mysteries of its underground world. Beneath the surface of this region, nestled between Italy and Slovenia, lies a vast network of caves—many still unexplored—once navigated by a group of fearless pioneers known as the grottenarbeiter, or “cave workers.”
This weekend, a conference titled “Grottenarbeiter of Yesterday and Today” will shine a spotlight on the remarkable history of these early explorers, whose daring expeditions in the 19th century laid the foundations for modern speleology, the scientific study of caves. The event will be held on Saturday at the Le Torri di Slivia farm near Trieste and will mark the 30th anniversary of the discovery of the Grottenarbeiter Branch in the Torri di Slivia Cave.
The conference, led by historian Maurizio Radacich and speleologist Giorgio Zanutto, is expected to draw enthusiasts from across the region. “The history of the grottenarbeiter is not just about exploration,” Radacich said in an interview ahead of the event. “It is a story of survival, ingenuity, and the relentless search for one of humanity’s most basic needs—water.”
Pioneers in a Thirsty Land
In the mid-1800s, as the port city of Trieste experienced rapid growth under the Austro-Hungarian Empire, it also faced a severe water shortage. Summers were particularly brutal, with the city’s water reserves often running dry. To address the crisis, the imperial government turned to the Karst Plateau, sending teams of local workers deep underground to find new sources of water.
These workers, dubbed grottenarbeiter, descended into natural caverns without the benefit of modern equipment. Their mission was not for glory or discovery; they were tasked with locating water in the complex and treacherous cave systems. Many paid for this work with their lives.
One of the most notable expeditions took place in 1841, when a team of grottenarbeiter finally succeeded in reaching the Timavo River, 300 meters below the surface of the plateau. The Timavo, a river that flows underground for much of its course, became a critical water source for Trieste.
“It was a breakthrough, both in terms of providing water for the city and in fueling interest in further exploration of the region’s caves,” Zanutto explained. “Their work is what sparked the birth of speleology as a formal discipline.”
A Modern Renaissance in Cave Exploration
Since those early days, the fascination with the Timavo River and the Karst caves has only grown. Modern speleologists have continued the work of the grottenarbeiter, mapping subterranean networks and making significant discoveries. One such milestone occurred three decades ago, when members of the Eugenio Boegan Cave Commission found a previously unknown branch of the Torri di Slivia Cave system. The new passage, named the Grottenarbeiter Branch in honor of the early explorers, stretches over 100 meters in length and features striking geological formations.
The upcoming conference will commemorate that discovery and include presentations on the latest advancements in speleology. One highlight will be a talk by Marco Restaino, president of the Adriatic Speleological Society, who will discuss the recent opening of a new “window” into the Timavo River—a previously unexplored cave known as Luftloch.
“The Timavo continues to intrigue scientists,” said Restaino. “We are just beginning to understand the full extent of this underground system.”
A Lasting Legacy
For Trieste and the surrounding Karst region, the grottenarbeiter are more than historical figures—they represent the spirit of resilience and exploration. Their work, born out of necessity, opened up a world that continues to captivate researchers and adventurers alike.
“Their legacy is not just in what they found,” said Radacich, “but in how they inspired future generations to keep searching, keep exploring.”
The conference is free and open to the public. For those who visit, it offers not just a look back at the past, but a glimpse into the future of cave exploration, where the pursuit of the unknown continues to drive human curiosity underground.
