Emyn Muil and Nindalf.
This map shows Frodo and Sam’s route after they landed under Amon Lhaw from the lawn of Parth Galen. They made their way east along the southern cliffs of Emyn Muil, trying to find a way down, and were finally forced north until they were stopped by the precipice shown in the preceding map. (The Breaking of the Fellowship; Bk 1; The Taming of Smeagol; Bk 2).
When Gollum had led them down the ravine he persuaded them to take his secret route through the marshes, and this was probably quicker (though more disagreeable) than going round to the north, although the marshes did not stretch very far that way. (The Passage of the Marshes; Bk 2).