How change the base path use by the routing system in laravel

I'm new in Laravel and i start to set my routes. I use laravel 5.1 on a local wamp server.

I'm on local, http://localhost/ttt/ goes on /public directory of Laravel.

When I try this :

Route::get('admin',function(){
    echo 4;
});

and go to http://localhost/ttt/admin, I got an error but when I do this :

Route::get('ttt/admin',function(){
    echo 4;
});

It work. I check the config and changed the 'url' value in config/app.php but it don't work.

Do you know if there is a kind of path used by the router that i can config ?

via Chebli Mohamed