http://www.rockpapershotgun.com/2011/04/18/20-best-things-about-skyrim/
"While the game’s pretty much the same size of Oblivion in terms of land mass, the inclusion of huge mountains – all of which you can climb to the top of, as well as often venturing within – means Skyrim has significantly more world to explore than its predecessor. “They create more time because you can’t just cut across them,” says Todd Howard."
You can and will traverse mountains.
"While the game’s pretty much the same size of Oblivion in terms of land mass, the inclusion of huge mountains – all of which you can climb to the top of, as well as often venturing within – means Skyrim has significantly more world to explore than its predecessor. “They create more time because you can’t just cut across them,” says Todd Howard."
You can and will traverse mountains.
this.