What is the fine-grained topic of the following text: The Great Himalaya Trail is kind of a vague concept … there are any number of possible variations … it is really just a network of trails (where there are any) pieced together to create a “higher route” linking the remote and rugged mountain districts in the highest regions of Nepal, and a “lower route” linking the slightly less remote and rugged hill districts. Only return the topic.
The Great Himalaya Trail