We're in the third phase of multi madness now. Expect a little more walking from here on out. This cache has three stages. The first stage will give you coordinates for the second stage. At the second stage, you will need to answer a question to get the coordinates for the final stage. Answer the question using the Certitude link below to get the final coordinates.
You can validate your puzzle solution with
certitude.
You will need a special tool to read the first and second stages, although you're probably already carrying this tool with you. More information on NFC tags in caching can be found in the description of this cache: GCB0VPG. Currently, iPhone users will need an app, such as "NFC Tools", to obtain the coordinates; Android users should be able to obtain them natively. The difficulty reflects finding all stages and being able to obtain the coordinates if you're not familiar with NFC technology.