Turning this piece was a great adventure, as is often the case with root burl.

This was turned from claro walnut root burl, which was filled with dirt and stones (which the root structure often picks up and assimilates).  As the piece was being turned and hollowed, the dirt and stones were exposed and removed, leaving the large opening on the side.

This piece reminds me of an ancient clay vase recently unearthed by archeologists.