Directly in front of the facade of the University, you'll find Calle de las Escuelas Menores (small colleges), the schools of which were originally dedicated to pre-university education. In the centre is the statue of Fray Luis de León. Note the walls filled with graffiti that reads Vítor or Víctor. It is said that university students painted it using bull's blood to celebrate passing their doctoral exams.
At the back of the square, on the left, you can enter the lovely patio of the Universidades Menores for free.