A work-in-progress riddle

As a Dungeon Master working to craft a story for a group of Dungeons and Dragons players, I find myself in need of a riddle. The riddle teller is the ghostly apparition of an elf noble inside his tomb. I am dissatisfied with this draft, so comments with suggestions are more than welcome.

The path beyond always unknown
The path behind soon overgrown
Know me to guess what lies ahead
I don't repeat, but rhyme instead.
If intelligence guides your mind
The greatest treasures you will find
What am I?

I want it to be a bit enigmatic, but I still want the players to have a chance to guess it without just rolling on a stat and asking me to tell them what their character realizes. Can you answer this riddle as it is written now, and can you improve it?