How can I get a particular directory name from url

Question

I want to extract the name of a particular directory of a URL and save it to a string from the server-side in ASP.NET C#. 

For example, lets say I have a URL that looks like this:

http://localhost:1096/directory1/directory2/default.aspx

How would I get the value of directory1 from the URL and save it to a string variable?

Thanks in advance.