What does the @routes map to in playframework

What does the @routes map to in playframework

In the playframework samples I see the syntax:
<a href="@routes.Application.index" class="btn">Cancel</a>
Inspite of having a controller class called Application.index the above
throws an exception. So I would like to know what does @routes expand to
at runtime and where does it point to since I have modified the code quite
a bit to remove some other routes. I need to remove this non existing
route but I would like to know how play actually maps them.