The Path of Solitude is a winding cliffside path that serves as a "stairway" between the lower and upper parts of Suicide Bluffs, outside the city of Athens. At the foot of the path is the great sword bridge, while at the top sits a gilded portal.
In God of War
In God of War, just after leaving the Temple of the Oracle, Kratos finds himself at the foot of the Path of Solitude. From there, he must cross the sword bridge. Optionally, however, he can make his way to the top of the winding pathway, where he will find the portal (which at the time is a mystery to him), a statue to Athena (though she will not respond to his prayers), and a hidden chest that holds a Phoenix Feather.
After destroying Ares, and learning that he would never be free of his nightmares, Kratos ascends the Path of Solitude, to the top of Suicide Bluffs, where he makes his futile attempt to end his life.
In God of War: Ghost of Sparta
Upon defeating Thanatos, Kratos finds himself (along with the now dead body of Deimos) at the foot of the Path of Solitude. In sorrow, Kratos picks up Deimos' lifeless body and carries it all the way to the top of the path. Once he has reached the topmost cliff, he finds the Grave Digger waiting for him, with a freshly dug grave for Deimos. Kratos lays Deimos' body in the grave and returns to Olympus.