The Rat: After discussion with co-owner PhilippeGPS we've decided to archive this. It has turned out to be too difficult to maintain. The original site was in a hollow stump, a regular size with good puzzles in it, but that one kept getting stolen, so we moved it farther from the trail, but that site kept getting covered by debris. We considered having someone else take it over, but there are external websites and emails that must be maintained and ownership transfer would be too difficult. The puzzle is multistage. The first stage is to copy the all-white image on the cache page and paste/edit it in some way to bring out the writing (there are two shades of white). In the spiral pattern there are a bunch of email addresses, but only one is real - the one with the period. I'm not going to detail the rest of it. There are many puzzlers in Silicon Valley who have solved it and can guide you through the rest, but the other sites won't be there much longer. The title is supposed to be a hint to solve the final step . The initials TUM indicate to use UTM coordinates once you get the final numbers.