The apartment is in a great location close to many of the sights you'll want to explore, walking distance to the train station for any day trips outside of Madrid and great cafes, restaurants, Prado Museum, Puerta del Sol and Plaza Santa Ana. There's also a small supermarket nearby so you can pick up essentials and some great options for breakfast as well. I would highly recommend Mar's apartment to families. You're in the thick of it within a couple minutes walk (literally) but also in an apartment that does not face the street, making it quiet and relaxing so you're not disturbed when you want to call it a night. I will definitely stay at Mar's place again next time I'm in Madrid.