<div class="wood">Wood
   <div class="marble">Marble
     <div class="water">Water
     </div>
   </div>
 </div>

In style element (<style>) within head element:

body {
  font-size: 18pt;
  font-weight: bold;
  color: white;
}
div.wood {
  padding: 1em;
  background-image: url('images/wood.jpg');
}
div.marble {
  background-image: url('images/marble.jpg');
  padding: 1em;
}
div.water {
  background-image: url('images/water.jpg');
  padding: 1em;
}