Access one web project from another web project asp.net mvc

As others have stated, it may be best to use ares in order to simplify the project, but if you want to keep them separated, I think the problem you are having is updating your routing.

By default, MVC applications have the following routing config (found in the Globals.asax.cs file):

    routes.MapRoute(
        "Default",                                              // Route name
        "{controller}/{action}/{id}",                           // URL with parameters
        new { controller = "Home", action = "Index", id = "" }  // Parameter defaults
    );

What you will need to do is look at the controller you're trying to wire up, and put in a route for that controller. For the sake of an example, I will assume your controller is called "AdminController":

    routes.MapRoute(
       name: "AdminController",
       routeTemplate: "website/admin/{action}",
       defaults: new { controller = "Admin", action = "Index"}
    );

    routes.MapRoute(
        "Default",                                              // Route name
        "{controller}/{action}/{id}",                           // URL with parameters
        new { controller = "Home", action = "Index", id = "" }  // Parameter defaults
    );

This example shows you how to map the desired route -- http://localhost/website/admin -- to the "Index" action on the "AdminController" object.

For more in-depth ASP.Net routing examples, you can look at the documentation here

Update: After looking at the example library in question (NopCommerce), it would appear they are using an explicit area registration. This is found in 'src/Presentation/Administration/AdminAreaRegistration.cs' :

using System.Web.Mvc;

namespace Nop.Admin
{
    public class AdminAreaRegistration : AreaRegistration
    {
        public override string AreaName
        {
            get
            {
                return "Admin";
            }
        }

        public override void RegisterArea(AreaRegistrationContext context)
        {
            context.MapRoute(
                "Admin_default",
                "Admin/{controller}/{action}/{id}",
                new { controller = "Home", action = "Index", area = "Admin", id = "" },
                new[] { "Nop.Admin.Controllers" }
            );
        }
    }
}

Hopefully this gives you a better idea of how this is done.