I first heard about memory techniques from the book Mind Performance Hacks by Ron Hale-Evans. Hack #4 is called Stash Things in Nooks and Crannies and describes how to make a memory journey through a single room. The hack can be read online here.
One of my favorite memory journeys is a walk through the city of Rethymno, Crete. It has 65 stages, though would have been longer if there had been time for one more visit. It took me three trips to the city just to get this far.
Here are a few highlights from the journey: