Someone

<html>
	<body>
		<div style="width: 100px; height: 200px; background-color: red;">
			<div style="background-color: lightblue; height: 30px; position: relative;" onmouseover="getElementById('bla').style.visibility='visible';">
				<div id="bla" style="background-color: orange; height: 30px; visibility: hidden;" onmouseout="getElementById('bla').style.visibility='hidden';">
					<div style="position: absolute;left: 50px; top: 10px;background-color: lightgreen; height: 60px; width: 100px;"></div>
				</div>
			</div>
		</div>
	</body>
</html>