Cave divers have explored the spring to depths exceeding 205 meters, making it one of the deepest karst springs in Croatia.
The spring is categorized as a rising karst spring, where water emerges from a vertical underground siphon.
The water color is a distinct, vivid turquoise due to the mineral composition and depth of the cave system.
The spring provides a significant portion of the base flow for the entire 212-kilometer course of the Una River.
The River Una Spring, known locally as Vrelo Une, is a karst spring located near Donja Suvaja in Croatia, serving as the primary source of the Una River. The spring emerges from a deep, water-filled karst chimney, with cave divers reaching depths of over 200 meters without finding the absolute bottom. The water maintains a constant temperature of approximately 8 to 10 degrees Celsius year-round. It is protected as a geomorphological monument of nature due to its complex hydrogeological features. The surrounding area features steep cliffs and dense vegetation, typical of the Lika region's karst landscape. The spring's outflow forms a turquoise pool before continuing its course through the canyon.
The small wooden observation deck located directly above the main pool.
Wear sturdy hiking shoes with good grip as the trail leading to the water's edge can be steep and slippery.
Bring a waterproof camera or phone pouch to safely photograph the proximity to the water.
Stay on marked paths to avoid disturbing the sensitive karst terrain and surrounding vegetation.
Attempting to climb the surrounding limestone cliffs, as the rock is often loose and unstable.
No swimming or water entry is permitted to protect the pristine quality of the spring source.
