Url rewriting addresses a different problem than what you are describing.
You can use an HttpHandler that handles requests to the path location
and parse the last segment to get your lookup key then simply pass execution off to an .aspx. Although you are passing execution off to a general page, the url will remain as entered.
I will provide an example. Give it a shot. here is a sample project
LocationHandler.cs
using System.IO;
using System.Web;
namespace DBHandler
{
public class LocationHandler : IHttpHandler
{
#region IHttpHandler Members
public void ProcessRequest(HttpContext context)
{
HttpRequest request = context.Request;
string page = Path.GetFileNameWithoutExtension(request.Url.Segments[request.Url.Segments.Length - 1]);
// for url ~/location/location33.aspx page will be 'location33'
// do something interesting with page, perhaps
context.Server.Execute("~/locations.aspx?locationId=" + context.Server.UrlEncode(page));
}
public bool IsReusable
{
get { return false; }
}
#endregion
}
}
locations.aspx
<%@ Page Language="C#" %>
<script runat="server">
protected void Page_Load(object sender, EventArgs e)
{
Label1.Text = Request["locationId"];
}
</script>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head runat="server">
<title></title>
</head>
<body>
<form id="form1" runat="server">
<div>
<asp:Label ID="Label1" runat="server" Text="Label"></asp:Label>
</div>
</form>
</body>
</html>
web.config excerpt
...
<system.web>
...
<httpHandlers>
<add verb="*" path="location/*.*" type="DBHandler.LocationHandler"/>
</httpHandlers>
</system.web>
...