Is there a way to put inner controls inside a ASP.NET Custom Control?

Question

I want to do something like (Updated example):

Answer 1

Follow up

Rex M provided the answer but just wanted to follow up on what I've also found for posterity.

It seems like you can do either:

OR

Then within code:

namespace Controls
{
    [ToolboxData("<{0}:Tabs runat=server>"), ParseChildren(true, "TabItems")]
    public class Tabs : BaseControl, INamingContainer
    {
        private TabCollection tabItems;
        [DesignerSerializationVisibility(DesignerSerializationVisibility.Content)]
        [PersistenceMode(PersistenceMode.InnerDefaultProperty)]
        public TabCollection TabItems
        {
            get
            {
                if (tabItems == null) 
                { 
                    tabItems = new TabCollection(); 
                } 
                return tabItems;
            }
        }

        protected override void Render(HtmlTextWriter writer)
        {
            writer.Write("
");
            int tabNumber = 1;
            foreach (Tab tab in TabItems)
            {
                string li = string.Format("
{1}
", tabNumber, tab.TabText);
                tabNumber++;
                writer.Write(li);
            }
            writer.Write("
");
            tabNumber = 1;
            foreach (Tab tab in TabItems)
            {
                string div = string.Format("
{1}
", tabNumber, tab.InnerHeading);
                tabNumber++;
                writer.Write(div);
                foreach (Node node in tab.NodeItems)
                {
                    string a = string.Format("{1}", node.Url, "Text holder");
                    writer.Write(a);
                }
                writer.Write("
");
            }
            writer.Write("
");
        }
    }

    public class TabCollection : List { }

    [ParseChildren(true, "NodeItems")]
    public class Tab
    {
        private string tabText = string.Empty;
        private string innerHeading = string.Empty;
        private string showOn = string.Empty;
        public string TabText
        {
            get { return tabText; }
            set { tabText = value; }
        }
        public string InnerHeading
        {
            get { return innerHeading; }
            set { innerHeading = value; }
        }

        public string ShowOn
        {
            get { return showOn; }
            set { showOn = value; }
        }

        private NodeCollection nodeItems;
        [DesignerSerializationVisibility(DesignerSerializationVisibility.Content)]
        [PersistenceMode(PersistenceMode.InnerDefaultProperty)]
        public NodeCollection NodeItems
        {
            get
            {
                if (nodeItems == null)
                {
                    nodeItems = new NodeCollection();
                }
                return nodeItems;
            }
        }
    }

    public class NodeCollection : List { }

    public class Node
    {
        private string url = string.Empty;
        public string Url
        {
            get { return url; }
            set { url = value; }
        }
    }
}

This will obviously be changing (mine's going to be reading from the web.sitemap among other changes), but this should get anyone with the same needs well under their way.