First, there is Macondo. The town has been on its own, hardly ever visited, but you feel its almost trapped in some foreign dimension, alone in a bracket of time where nobody had even died yet, hence, "they had not even built a cemetery".
Jose Arcadio, the town's founder is a mirror image of Macondo. He is a loner, obsessed with things that only matter to him, and he is also a demo of solitude.
The death of Aureliano at the beginning of the story shows a man abandoned by his society and circumstances, wondering away at times long gone.
The final days of rain send Macondo back to its bare origins, even after the invasion of capitalism, imperialism, and all the forms of government that took it over.Again, solitude is their fate.
The end of the story, which shows that Macondo had a pre-destination to be what it is, is the basic final demo that this place was meant to suffer from solitude.