I want to specify that if anything entered in the url address other than existing routes (in routes.php, then show 404 page.
I know about this:
App:
This is my approach just for displaying the error 404 with a template layout. Just add the following code to /app/start/global.php file
App::missing(function($exception)
{
$layout = \View::make('layouts.error');
$layout->content = \View::make('views.errors.404');
return Response::make($layout, 404);
});