* {
	margin:0;
	padding: 0;
}

#contenedor {
	margin: auto;
	border: 1px solid black;
	width: 80%;
	height: 900px;
	text-align: center;
	position: relative;
}


.foto {
	display: inline-block;
	border: 1px solid lightgray;
	padding: 1em;
	margin: 1em;
	box-shadow: .5em .5em .5em lightgray;
	background: white;
	transition: transform 1s; /* para que tarde 1 segundo en agrandarse la foto*/
}

.grandes {
	display: none;
}

.foto:hover .grandes {
	display: inline-block;
	position: absolute;
	bottom: 2%;
	left: calc(50% - 100px);
}

div img {
	width: 100px;
	height: 100px;
}
div .grandes {
	width: 200px;
	height: 200px;
}