Describe symbolism in The Letters of J.R.R. Tolkien by J.R.R. Tolkien

Mordir is a fictional location, the name for the Evil Sauron's powerbase in Lord of the Rings. Mordor is Sauron's political jurisdiction, and it is mentioned in a number of the letters interspersed throughout the book. There are not a large number of details provided regarding Mordor, mainly that it is ominous and is a symbol of two things. The closer the good characters get to it, the worse and more frightening their situation becomes. Secondly, this means they are on the right track, as they have to go there in order to destroy the Ring. In this respect, the more dangerous the conditions, the more they would have to overcome their natural aversions to proceed.