When I view the last 50 posts, in the right column there is the list of the forum in which the post was created. If you click on the forum name, it's supposed to take you there, but lately this has been broken. The link is like this example:
Where **MYIPADDRESS** replaces my real IP (that is, the url has my ip in it, but I removed it for this post)
It will then say "The specified forum no longer exists or never existed."