ナショナルジオグラフィックさんのインスタグラム写真 - (ナショナルジオグラフィックInstagram)「Photo by Robbie Shone @shonephoto Slovenia has many wonders, but to me it's famous for its river caves—it's the birthplace of speleology. Pictured here is Križna jama (cave), named after a nearby church of St. Cross (Sv. Križa). The cave features a chain of underground lakes with emerald green water. It's one of the few touristed caves in Slovenia that doesn't contain concrete pathways or harsh lighting, which is harmful to the cave environment. It's considered to be one of the most beautiful and best-preserved caves in Europe—and the world.」9月14日 19時38分