The Click Map part of your report can be found by selecting this option inside of your report. The click map is included in the menu options along the top of your report overview.
This part of your report will give you a visual display of the most clicked links in your message. The larger the hot-spot is, the more link clicks you have on that link.
If you notice that not many of your recipients are clicking on a link / call to action which is down past the halfway mark in your email, you may want to move your link / call to action further up the email for future sends.
The click map is a handy visual guide which you can use to determine if links and your call to action should be relocated to a more prominent position.