Confession time, I don't think it is possible to depict solitude. At the same time I thinkI bagged couple of shots that come close enough. Solitude is the kind of eerie feeling that sneaks by inside and is not necessarily connected to a person being alone.
Anyhow, here's my favorite one. I took it at and old railway station in Sevilla that nowadays is a cinema/shopping center. Seemed to be the hangout place for local cool youth. However, there was also this empty second floor space. I was so excited to spot the guy sitting there alone.
Apparently Sevilla was the place to capture solitude, because all of the following shots come from there as well.
One way or another places filled with graffiti give me some kind of solitude-vibe.
That pigeon turned around and walked towards the orange trees, it did not jump nor fly towards the city across the river.