What is calling the "index.html"(eventmenu.html)

in this codepen -> http://codepen.io/auching/pen/vyzJg

i can not see anything "calling" the event-menu.html, i see the $stateProviderRoute, BUT nothing is provided in the start of the application, i have to click in some of the List item to change the URL, so the stateProvider can work using the URL, but the event-menu(start) never is called, so HOW it know that have to "start" the application in the event-menu

i can change all html codes in its own file, and leave in the index.html just this:

<div ng-controller="MainCtrl">       
      <ion-nav-view></ion-nav-view>
    </div>

but in the MainCtrl, there is nothing saying ex:

onload="startApplicationCallingTheEventMenu.html()">

sorry if its a confuse, i just need to get this point so i can start working with $routes