Other than by whatever method you initially found that page, no you will not be able to find it if you have cleared your History.

You could consider normally working with your history being saved, but selecting Private Browsing - Use Firefox without saving history when you do not wish the history etc to be explicitly saved. (You are able to manually bookmark pages still whilst in private Browsing.)

If you've visited the page recently and didn't clear the cache then you can look on the about:cache page to see if you can identify the site.

You can look at this extension for easier access to files in the cache.

• Cache Viewer: https://addons.mozilla.org/firefox/addon/2489