Poem analysis #3:

"Merlock Mountains": (see: https://www.furaffinity.net/view/49495732/ )

"Marsh of Tode": Possibly the Dead Marshes of Dagorlad (even Gollum remebers stories about that place, back when he was still "innocent" Smeagol). Of course, any marsh, swamp, fenn, moor can be dangerous, even for the sure-footed.

"Wood of hanging trees...": Obviously, the Old Forest on the Shire's borders, but can also mean Fangorn (of which the Old Forest was once a part of). "Spider-shadows" seems to suggest Mirkwood.