Muros=paredes? Is this perhaps a difference between outside walls (of the house) and inside walls (of a room)?
Can someone please answer this without linking to another comment? The app doesn't let you follow the link
This is an answer from Paulenrique: "Muro has no ceiling over it. So inside a house you have paredes. What separates your house from your neighbor's is um muro".
Interesting that the picture Duo gives for parede is an outside free-standing wall and the Great Wall in China!