Junior researcher, teaching assistant, Ph.D. candidate, and part-time geek.

I also have an amateur passion for public transport systems, and I collect subway maps.

Please pay attention to each photo's license! Most of them are licensed Creative Commons Attribution-Noncommercial-No Derivative, which means that you are free to share but:

1. You must attribute the work by stating my Flickr username (jcraveiro) with a link to the original photo. Such attribution must not suggest that I endorse you or your use of my work.

2. You may not use my work for commercial purposes.

3. You may not alter, transform, or build upon this work.