The Forbidden Falls is a location in the Smurf Forest that appears in the 2011 Smurfs movie. During the early part of the film, as Gargamel chases the Smurfs after finding their village, Clumsy accidentally heads towards the falls when a partially obscured sign tells him to "go this way" when it actually warns him "do not go this way". Papa Smurf and a few other Smurfs chase after Clumsy and try to rescue him when he falls over the precipice, hanging onto a root for dear life. However, at that point a portal opens that sucks the Smurfs into it, taking them through time and space into modern-day New York City.
In The Smurfs 2, Papa Smurf used water from the grotto of the falls to create the smurfportation crystals in order to travel directly to Patrick and Grace Winslow's apartment and back to the Smurf Village.