如何在ASP.NET中获取IIS虚拟目录的物理路径

I have a virtual directory on IIS7 that is pointing to a folder inside my application root. I have some files there and I need my asp.net application reads and lists those files. How can I do that? Is there any way to know which is the real physical path of a virtual directory from asp.net? I'd really appreciate any help. Thanks.I have a virtual directory on IIS7 that is poin