Migrating to new site

Selected answers from the Dumb SEO Questions Facebook & G+ community.

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  orel cohen: I had a site that was ranked well and later on I've switched it to a new site without proper migrating. how can i find the old urls that were before the change?
  
  
  I've tried with frog crawler, in google site:, in case the didn't have webmaster tools and they open new one now can it work?
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  Michael Cloke: Go to archive.org type in the old URL.
  Click on one of the highlighted dates and you will see the old site. Now you can click on the nav buttons and see the old urls in the browser. 
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  orel cohen: Isn't there a way to get a list of those and not do it manually?
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  Collin Davis: If you have taken a backup of the site at some point of time, then you should get URLs or else as Michael mentioned, you will require to do it manually
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  Matt Hintze: Depending on when you migrated the old site, there might be some or all of your URLs in Google's index.  ;You can use the use the operator in Google's search: site:www. your site here .com
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  orel cohen: They migrated it 3 months ago so...