The facade dates from 1529, and is considered a masterpiece of the Plateresque style. It is built, like most of the buildings of this era in Salamanca, from Villamayor stone. The front facade has three altarpieces, and at the top is a richly decorated crest. You can see the large medallion of Spain's Reyes Catolicos, with the inscription "The University of the Kings and the Kings of the University". There are also shields which are said to either represent Carlos I and his wife, or Hercules and Hebe. And of course, there is the famous frog on the facade, with various stories to explain its purpose.