Foursquare just raised $50 Million at a post money valuation of $600 Million. Andreessen Horowitz led the round.

The CEO Dennis Crowley in a blog post said “Today, we’re really excited to announce that we’ve raised $50 million in funding so that we can keep working towards our goals. The new round, led by Andreessen-Horowitz, includes our current VCs (O’Reilly AlphaTech Ventures and Union Square Ventures), as well as Spark Capital. Having our current investors double down on us is a tremendous gesture of support for foursquare and for the direction we’re headed.”

He further stated that “The additional capital will allow us to move more quickly; we can hire more engineers (we’re hiring in New York and San Francisco!), evolve our merchant offerings, expand internationally, and try a ton of new things.”

In June of last year, Foursquare raised $20 million at a $95 million valuation.