Juliana's apartment is easy to access with the Renfe Cercanias trains and pretty close to Madrid's Atocha trainstation. I stayed with a friend at Juliana's place and we had a great time. Juliana and her partner are super friendly and good to chat with. Their dog is also very cute and every morning we would get a vegan breakfast (toast, jam and fresh fruits).
Would definitely come back to stay at Juliana's whenever I'm in Madrid!!