Gallery in post

Hello,

I would like to have a Gallery in a Post.
I can´t figure out how to do it without installing an external plugin...
In this case, could you recommend one ?

Thanks in advance.

The only two ways that comes to my mind is either with use of [gallery] shorttag, or with use of widget for example Image Show Pro and publishing it in position of your liking + selecting only one page/post to show it.
Other way is to use a plugin and its shorttag.