In the past, we changed our website's look and feel and we also changed lots of URLs. At that time, we did not care and applied 302 redirects from old URLs TO new URLs. Now the problem is that Google still keeps plenty of our old web pages in its index. We found some of these old pages and redirected (301) to our new website pages. But, i wonder there are still hundreds of such old web pages which need to be redirected to correct pages of today.

Please suggest me what should I do to find out those old pages in Google's Index? Is there any tool for that? If yes, please suggest me.