When you're 18-year-old freshmen and your safe is in Fort Knox, a mere college pad simply won't do, boys 'n' girls - and certainly not a dorm at NYU.

So the Olsen twins - the ubiquitous Ashley and Mary-Kate - reached into their petty-cash drawer and pulled out $7.3 million to buy the world's biggest dorm room, at the Morton Square condo on West Street in lower Manhattan.

Star magazine got an exclusive look inside the acting and merchandising moguls' new 5,725-square-foot, 15th-floor penthouse as it was being remodeled. The tab has additional tidbits on the posh digs in the issue that went on sale this week.

The apartment consists of four adjoining units, which have been converted into one large space. It boasts two master bedrooms with a bathroom in each, a private elevator and fantastic views of the city.

It should make writing term papers a lot easier.