A Letterbox Hybrid which is not hidden at the posted coordinates (but is nearby), and requires a 3 mile roundtrip hike. In addition to the normal logbook and trade items, it also contains a letterbox stamp, inkpad, and stamp book. Please do not remove the stamp, ink pad, or stamp book. THEY ARE NOT TRADE ITEMS!. 
Thrain I found the Lonely Mountain, in which an underground city was formed. The Kingdom of Erebor was abandoned, then reestablished by Thror. There are six outer guard posts, but only Ravenhill is listed in any tales. It was here that the dwarves of Thorin Oakenshield visited, and later it was here where a last stand was made. Bilbo Baggins was here when he was hit on the head with a rock and knocked unconscious during the Battle of the Five Armies.
To reach Ravenhill, start at the trailhead, then take a side trail called the '200.' The best plan is to make for either Cerebrum Rock or The Only One He Ever Feared. The letterbox is NOT hidden at the posted coordinates. From the posted coordinates, project a waypoint at 110 degrees true north to 792 feet.
This is a letterbox hybrid. In addition to the normal logbook and trade items, it also contains a letterbox stamp, inkpad, and stamp book. Please do not remove the stamp, ink pad, or stamp book. THEY ARE NOT TRADE ITEMS!
A basic letterbox hybrid should consists of the following (this is my criteria not that of Groundspeak):
1. a stamp
2. a distinct pad of high quality art paper for collecting stamps, that is distinct from the log book, and is large enough to leave impressions from your own personal stamp.
3. An inkpad. Some geocachers omit this because it can dry out, but water can be added to the pad if needed.
A "true" letterbox would also have the following elements:
4. a hand carved stamp
5. require route finding addition to GPS coordinates: in other words the GPS leads you to the starting or intermediate point, but then a description is necessary to find the final container.
6. Be listed on letterboxing.org or similar listing.
This is a true letterbox hybrid, having all of the above components.