<!DOCTYPE html>
<style>
body {
margin: 0;
}
iframe {
display: block;
width: 300px;
height: 300px;
position: absolute;
background: white;
}
.i1 {
top: 50px;
left: 50px;
}
.i2 {
top: 100px;
left: 100px;
}
</style>
<iframe class="i1" src="lipsum.html"></iframe>
<iframe class="i2" src="lipsum.html"></iframe>