Laravel using multiple route files

I used this trick when I had multiple domain names pointed at a single app.

Edit:

/app/providers/RouteServiceProvider.php

protected function mapWebRoutes(){
    Route::group([
        'middleware' => 'web',
        'namespace' => $this->namespace,
    ], function ($router) {
        require base_path('routes/chambers/suffield.php');
        require base_path('routes/chambers/granby.php');
        require base_path('routes/web.php');
    });
}