I greatly enjoyed the cache puzzle The Fine Art of Diplomacy by Lostinthegarden. It was a really neat way to enjoy art and solve a geocache at the same time. This cache is a sequel of sorts- it has a lot in common with that puzzle but also has quite a few differences. I recommend you start by solving their geocache first, and you may find you have what you need to get going with this puzzle.
The Undead are trying to tell you, through art, where the geocache is. Once you find the undead, you need to understand what they mean.
1. Haqrefgnaqvat fbzr bs gur onpxtebhaq bs gur Haqrnq znl fcrrq hc gur fbyivat.
2. Gur Haqrnq ner ubeevoyr fcryyref ohg nera'g sbetrggvat nalguvat.