Looking on the internet deeply has found these results:

Go to the mountains is the most popular phrase on the web.

Go to a mountain 11,100,000 results on the web	Go to the mountains 12,550,000 results on the web More popular!
Some examples and use cases from the internet:	Some examples and use cases from the internet:
I want to go to the mountains and learn to snowboard. Then the water will go to Black Mountain Village. You go to the top of a mountain and they leave you there with a pack of... I know you will go to Black Mountain. You go through a mountain tunnel, there's a lake. Say... why don't we go to that mountain once. I finally manage to get my editor, Masao Masuda, to invite me to a traditional tea ceremony. We go to a mountain near Hakone, enter a small room, and his sister, dressed in the ritual kimono, serves us tea. We can go to the mountains whenever you want to.	I would go to the mountains when young. If I don't do that I will go to the mountains and die as a itch jackal. Why? He promised to go to the mountains with his wife. He said, "Go to the mountains and get their good tidings." We can go to the mountains whenever you want to. We should go to the mountains, look for other tribes. If we move to Thailand, I don't know, it would be very hard Maybe I'll miss the snow, then I won't be able to go to the Mountains and go snowboarding I want to go to the mountains and learn to snowboard.

Go to a mountain

11,100,000 results on the web

Go to the mountains

12,550,000 results on the web

More popular!

I want to go to the mountains and learn to snowboard.
Then the water will go to Black Mountain Village.
You go to the top of a mountain and they leave you there with a pack of...
I know you will go to Black Mountain.
You go through a mountain tunnel, there's a lake.
Say... why don't we go to that mountain once.
I finally manage to get my editor, Masao Masuda, to invite me to a traditional tea ceremony. We go to a mountain near Hakone, enter a small room, and his sister, dressed in the ritual kimono, serves us tea.
We can go to the mountains whenever you want to.

I would go to the mountains when young.
If I don't do that I will go to the mountains and die as a itch jackal.
Why? He promised to go to the mountains with his wife.
He said, "Go to the mountains and get their good tidings."
We can go to the mountains whenever you want to.
We should go to the mountains, look for other tribes.
If we move to Thailand, I don't know, it would be very hard Maybe I'll miss the snow, then I won't be able to go to the Mountains and go snowboarding
I want to go to the mountains and learn to snowboard.