mika
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I don't know what the "Heroes" player was thinking about, but so far, this is all I've found, and it's likely been discussed here before.
Moria (correctly spelled Moria – from Sindarin Moria; also known as Khazad-dûm, Khadhodhrond, and Furu-nargian) is a vast underground city in the Misty Mountains of Middle-earth in J.R.R. Tolkien's legendarium. Its extensive network of tunnels included deep mines and huge halls connected by passages. For many thousands of years, Moria was inhabited by the dwarves of the Durin clan.
However, I must admit that I probably won't be of much help with these hints, as I'm not familiar with the Lord of the Rings or Tolkien. Unfortunately, it's not my area of expertise.