What do the mountain represent?

There are references to mountains but I do not think they are of any substantial importance in the play. Mountains tend to represent stability and time. Consider act 5 sc 1 when Hamlet laments Ophelia's death.

'Swounds, show me what thou'lt do.
Woo’t weep? Woo’t fight? Woo’t fast? Woo’t tear thyself?
Woo’t drink up eisel, eat a crocodile?
I’ll do ’t. Dost thou come here to whine,
To outface me with leaping in her grave?
Be buried quick with her?—and so will I.
And if thou prate of mountains let them throw
Millions of acres on us, till our ground,
Singeing his pate against the burning zone,
Make Ossa like a wart! Nay, an thou'lt mouth,
I’ll rant as well as thou.