The Cheile Bicazului (Bicaz Gorge) is one of the most dramatic mountain road journeys in Romania, 35 km west of Piatra Neamț on the road to Transylvania. The gorge cuts through a massive limestone massif, and in the narrowest section — called "Gâtul Iadului" (the Neck of Hell) — the walls close to within a few metres of each other while the road squeezes through below. Rock climbers use the walls on both sides.
At the western end of the gorge lies Lacul Roșu (Red Lake), a mountain lake formed by a natural landslide dam in 1837. The submerged trunks of the drowned forest still protrude from the surface, giving the lake an eerie character. Both the gorge and the lake are within the Cheile Bicazului–Hășmaș National Park.