Ordinarily, Fools focus on public companies. What they're doing. How much they're earning. We don't spend a lot of time looking at private companies because, well, they're private. You can't invest in them. Neither can we. So why bother?

Well, every once in a while, it pays to pay attention to the private world. News has just broken that the Netherlands' Lego has sold off a 70% interest in its 128-acre Legoland California theme park, and three other parks as well.

It's not Lego's sale of the parks per se that interests us. Lego's bleeding cash and has been for some time. Over the past two years, the company has posted losses of $495 million, about $35 million more than it will make from the Legoland deal. What's more, the company can't afford to make the necessary improvements to its parks to stay competitive with theme-park rivals. Since the end of 2003, Lego has invested a measly $11 million in Legoland. So Lego's reason for selling is clear.

What's less clear, and more interesting, is private equity firm Blackstone's rationale for anteing up $460 million to acquire the majority stake in Lego's parks. You might consider this too whimsical a deal to interest a serious buyout heavyweight like Blackstone. There are no satellites involved. Not even chemicals or hotels.

But Blackstone already owns a big piece of the entertainment field. Its Merlin Entertainments subsidiary calls itself the ninth-largest theme park operator in the world and owns 28 attractions in Europe. Clearly, when Blackstone saw Legoland's "for sale" sign, it judged the half-billion asking price a bargain worth accepting.

Which suggests to this Fool that opportunity may lie hidden among the nation's publicly traded theme parks as well. A company like Blackstone doesn't have to take just any deal that comes along. In addition to its private holdings, Blackstone has sizeable stakes in any number of public companies: Allied Waste (NYSE:AW), American Axle (NYSE:AXL), and, more recently, Celanese (NYSE:CE). If money was burning a hole in Blackstone's pocket, it could have simply added to its current stakes in any of these public companies.

When Blackstone instead ups its stake in theme parks, investors should take notice. Value hunters might want to start taking a closer look at Disney (NYSE:DIS), Cedar Fair (NYSE:FUN), Six Flags (NYSE:PKS), and Motley Fool Rule Breakers pick Great Wolf (NASDAQ:WOLF). I know I will.

Toy with more Lego Foolishness:

At the time of publiciation, Fool contributor Rich Smith held no financial position in any of the companies mentioned in this article.