You can find the Integrations Page in your MailChimp account by going to account > integrations.
Here, you can connect or disconnect your integrations.
If you're looking for a list integration, those can be found by going to list tab > import.
Which will take you to:
For a quick view of all current integrations and a link to more information on each integration, visit http://mailchimp.com/features/integrations/.