agltbialik: Goodnight sweet prince.
The final was muggled again (and no one got to find it! I lost $$$ on this one this time), and I think the people who did it will just keep coming back. It doesn't seem welcome there. So, I decided to kill the entire thing since every stage was so intricately placed and linked that changing the location of the final would mean re-fitting the entire cache as a whole.
I have an idea for a similar cache that might be much more muggle proof (at least the steps leading to the final will be) but it will have to be in another area of the city.
Thanks to all that completed this adventure!