How do you make a tunnel in hammer?

Yeah read title.

Use the arch primitive in brushes.

Yeah post in the question megathread thread.

Depends on what sort of tunnel do you want to make.

Just a round tunnel I am a noob map maker that means I have no idea what a
arch primitive is.

Look up some basic tutorials if you’re that low.

[hd]http://www.youtube.com/watch?v=vwHydUP-7Bc&hd=1[/hd]

From 5:25