Calle de O'Donnell, 27, 6º Derecha, Madrid, Spain
620 93 62 77
True to its name (Hostal Arco Iris means Rainbow Guest House), this small hotel is colorful and modern. It was obviously remodeled a few years ago to good effect and the rooms are comfortable and contemporarily decorated. The single and double rooms are available with a private bath or a shared bath. There's free Wi-Fi and an Internet station in the hallway. Retiro Park is nearby.