I always have difficulty remembering how to find the name and directory of the executing application or website. Here is the breakdown for reference. More to come
Get Directory of current application root - System.Web.HttpContext.Current.Server.MapPath("")
Get Directory of current application – System.Web.HttpContext.Current.Request.PhysicalApplicationPath
Get Directory of current page request (entire path) - Request.MapPath(Request.QueryString["filename"])
Get name of the current assembly - System.Reflection.Assembly.GetEntryAssembly().GetName().Name
Get executing assemblies location (.dll files in temp) - Path.GetDirectoryName(Assembly.GetExecutingAssembly().Location)