I stayed at Pedro's place while on a solo trip to Madrid and had a wonderful stay there. The neighborhood felt safe, even as a solo female traveler, and I was within 10 minutes' walking distance to Retiro Park and several metro stations. I found the place a little cold (in December), despite the heating system being set at ~26 degrees Celsius, but with layers and the blankets that Pedro offered, this was hardly a problem. The hot water worked great, which was more important anyway. Pedro was very kind and was quick to respond the couple of times I reached out. The bed was not particularly comfortable, but it did the trick! I would recommend staying here for a clean, well-situated, comfortable stay with an excellent host.