The River Vouraikos has carved a dark, narrow gorge out of the rock. A picturesque cog railway runs along part of this, following the vertiginous path of the old narrow-gauge railway, through tunnels, and sections overlooking steep drops, bridges and viaducts. It takes around an hour to cover the 22km that separate Diakofto and Kalavrita, a winter sports resort. The gorges are also home to two monasteries: Agia Lavra and Mega Spileo, the church of which boasts fine frescoes.