.two-column-div {
column-count: 2;
}
<div id="content">
<div id="left">
<div id="object1">some stuff</div>
<div id="object2">some more stuff</div>
</div>
<div id="right">
<div id="object3">unas cosas</div>
<div id="object4">mas cosas para ti</div>
</div>
</div>