Thjorsa River

Þjórsá is Iceland’s longest and most powerful river and has played a decisive role in shaping the landscapes of South Iceland for centuries. The river originates in the Icelandic highlands, where glacial and spring-fed waters merge to form a vast and forceful river system that flows from the interior toward the lowlands. Its size and strength clearly reflect the natural forces that have shaped the country over time.

Along its course through South Iceland, Þjórsá is closely connected to a number of well-known natural attractions. The river flows past Þjófafoss and Hjálparfoss, where immense volumes of water cascade over dark volcanic rock, creating dramatic and powerful waterfalls. Nearby lies Háafoss, one of Iceland’s tallest waterfalls, plunging into a deep canyon and further illustrating the scale of the river system.

Þjórsá also flows through Þjórsárdalur, one of the most diverse natural regions in South Iceland. Here, fertile valleys, expansive lava fields, and waterfalls come together to form a rich and varied landscape. Close by is Gjáin, a lush green oasis known for its small streams and waterfalls, as well as Gjárfoss, which is admired for its unique basalt formations and tranquil surroundings.

The landscape surrounding Þjórsá has been shaped by volcanic eruptions and glacial floods over thousands of years. Lava fields, palagonite formations, and exposed rock layers along the riverbanks provide insight into Iceland’s geological history. Overlooking the area is the volcano Hekla, one of Iceland’s most active and influential volcanoes, which has had a profound impact on both the natural environment and human settlement in the region.

Þjórsá has also played a significant role in Iceland’s history of energy production. Hydropower facilities such as Sultartangi Power Station highlight the importance of the river in supplying renewable energy to the country. Early debates surrounding the utilization of Þjórsá became an important part of Iceland’s broader discussion about balancing natural resource use with environmental conservation.

Today, Þjórsá stands not only as Iceland’s most important river by volume and length, but also as a centerpiece of natural exploration in South Iceland. Its waterfalls, valleys, and surrounding landscapes attract travelers who wish to experience the power, diversity, and geological history of Icelandic nature in a single region.