The water in the Grassano stream maintains a constant temperature of approximately 14°C throughout the year due to its spring-fed origin.
The park is situated within the Geopark of the Sannio, a UNESCO-recognized site noted for its complex geological history.
The emerald hue of the water is a result of the specific mineral composition and the reflection of light off the limestone riverbed.
The park was established to preserve the unique riverine ecosystem of the Grassano stream, which is a tributary of the Calore River.
Parco del Grassano is a natural park centered around the crystal-clear, emerald-colored waters of the Grassano stream in San Salvatore Telesino. The park is characterized by its karst spring, which maintains a constant cool temperature year-round. Visitors can navigate the river via small wooden canoes, the park's signature recreational activity. The grounds feature expansive lawns, shaded woodland areas, and designated picnic zones for public use. It functions as a protected naturalistic area rather than a traditional zoo, despite its classification. The river ecosystem supports diverse flora and fauna, including ducks and freshwater fish visible through the transparent water. Wooden walkways and footbridges facilitate access across the marshy terrain and riverbanks. The site is a popular destination for families looking for outdoor recreation in the Sannio region. It remains open as a recreational green space with established paths and infrastructure for water-based activities.
The wooden bridge spanning the narrowest, most vivid emerald section of the stream.
Book canoe rentals in advance if visiting on a weekend or public holiday, as availability is limited.
Bring insect repellent as the combination of woodland and stream creates a high-density mosquito environment.
Wear water-friendly footwear if you plan on participating in canoeing activities.
Do not attempt to swim in the stream, as swimming is prohibited to protect the delicate aquatic habitat.
Open daily during the high season; typically closed or restricted to weekend-only operations during winter months.
Maintain noise levels to protect local wildlife; stay on marked paths to prevent soil erosion in sensitive marsh zones.
