I have this razor script which generates 2 levels of navigation from the current page. It seems to be working fine until I wrap the second foreach statement in a <ul>, then it throws an error saying the variable doesn't exist in the current context.

Any ideas?

@inherits umbraco.MacroEngines.DynamicNodeContext


@* Ensure that the Current Page has children, where the property umbracoNaviHide is not True *@
@if (Model.Parent.Children.Where("Visible").Any())
{
<nav>
    <ul>            
        @* For each child page under the root node, where the property umbracoNaviHide is not True *@
        @foreach (var childPage in Model.Parent.Children.Where("Visible"))
        {
            <li>
                <a href="@childPage.Url">
                    @if(@childPage.HasProperty("navigationDisplayName") && @childPage.GetProperty("navigationDisplayName").Value != String.Empty)   
              {
                 @childPage.navigationDisplayName;
             }
             else {
                    @childPage.Name;
              }
             </a>
                @if (childPage.Children.Where("Visible").Count() > 0)
                  {
                     <ul>
                        foreach (var childChildPage in childPage.Children.Where("Visible"))
                       {
                         <li>
                            <a href="@childChildPage.Url">
                              @if(@childChildPage.HasProperty("navigationDisplayName") && @childChildPage.GetProperty("navigationDisplayName").Value != String.Empty) 
                          {
                             @childChildPage.navigationDisplayName;
                            }
                         else {
                                @childChildPage.Name;
                         }
                         </a>
                            </li>
                       }
                     </ul>
                   }
            </li>
        }
    </ul>
</nav>
}