Varkala beach and Varkala cliff : Yes, this has been my most fav beach so far , around 30 kms from the city. You can take a train which shall drop you to the varkala junction but I chose to ride .
The Varkala beach is also known as PaapNasham beach. The nightlife here is pretty awesome. I visited this beach thrice and you get to enjoy a pretty chilled nightlife with some foreigners.