The Glyrshar Canyon was a geological feature on Bajor. It was the site of the planet's tallest waterfall, and one of the few natural wonders that made it through the Cardassian Union's Occupation of Bajor unscathed.
In the year 2385, Benjamin Sisko and his family - Kasidy Yates and their daughter Rebecca; and his son Jake Sisko and his wife Azeni Korena - took a vacation at Glyrshar Canyon. While there, they played baseball and had holographic pictures taken of their stay. (DS9 novel: Sacraments of Fire)