Charo's home has a very good accessability to the main street like Gran Via or Puerta del Sol which takes just 10~15 minutes walk. We could visit Palacio Real in the morning then came back home to have a spanish siesta, but still had enough time to visit museo del Prado in the afternoon. Every time we moved on foot.
You can even find many affordable bars around this area.
We stayed just 1 night and it's a pity that we had to go sleep even though Charo suggested having wine together in the night because we were too tired after 13 hours flight and all day sightseeing.