I wanted to share a website I was looking at that gives a good overview and a checklist when designing a PBL. Since I am newer to using PBLs in my classroom I find it helpful to have examples and a list to ensure I am completing all the areas of learning I need to make it successful for my students.
http://wveis.k12.wv.us/teach21/public/project/Guide.cfm?upid=3307&tsele1=4&tsele2=109
Its a great projects that connects to major ancient civilizations to the modern world