On the Road with Marco Polo
http://edsitement.neh.gov/curriculum-unit/road-marco-polo
This website was developed by the National Endowment for Humanities. This features interactive lessons for students. This site is great because it involves a variety of skills: reading, writing, and map sills. Although the lessons are designed for elementary students, they can easily be adapted to older students as well. I would use this in my 10th grade world history class, as an internet homework assignment.