Hostal Castilla II Puerta del Sol

Address: Calle del Marqués Viudo de Pontejos, 2, Madrid. A quick check on the map can help confirm the entrance and the easiest approach.

Looks like they're open every day, so you don't need to worry about timing your visit around a closed day.

Yes, open around the clock, every day. Great if you need to stop by late at night or early in the morning without worrying about hours.

According to available data, this is a guest house. Guest houses are often smaller and more personal than standard hotels, with fewer rooms and a quieter atmosphere.

Wi-Fi is available. Speed and stability can vary a lot — if you're doing serious work, having a backup is never a bad idea.