Mesopotamia and the Trilogy

[Diamond18]

And doesn't it say somewhere else on this forum that there's a city in Mesopotamia called Moriah?

I said that somewhere else, but I think now that I was wrong. In the same letter Tolkien addresses 'the land of Moriah' but I have difficulty understanding what he was talking about because I was not able to read the letter he was replying to. My befuddled memory combined the two, forgetting that Erech was the city in Mesopotamia. There is a hill in Palestine called Moriah, however (I found that in the dictionary).