Last July (in 2014) I traveled by myself to Iceland. I arrived at the Bus Hostel Reykjavik in the evening, and the following day I walked around Reykjavik to do some sight-seeing. On the back of the map I got from the hostel, there was an ad for a museum about vikings. I decided to go there, and by the end of the tour you had the option of dressing up as a viking. I of course wanted to do this, and I also wanted a photograph of myself in said costume.
So I walked up to a random guy and asked him if he could take a photo of me. He instead suggested we take a photo together. And so we did.
Turns out, he was also a solo traveler staying at the Bus Hostel. We ended up spending the week together, and now, a year later, we are engaged!