Today at lunch, the Catalans told me about this, castell building, which is a tradition here.  They make the little kid at the top wear a helmet now because the towers fall sometimes.  One of the pathologists said that she used to do this and that they have to practice.  They can make really neat-looking ones and it's kind of an art.  I love their food here too.  Lot's of tomatoes and olive oil!  I will miss Spain.