Anderson Cooper tweeted a photo of himself last night shirtless and covered in mud, asking his followers:
"I'm off for a few days. From this photo can you guess where in the world I am? Exact location?"
UPDATE from Anderson: "great guesses. some got it right! I was at volcan el totumo. Mud volcano near Cartagena, Colombia…You go to the top of the volcano and go into the warm mud. Its really weird, but fun. Colombia is a beautiful country."