Thanks for the replies! I ended up sending an email to the Hotel Atlantico and got the following response:

Now is all Hotel Atlantico
Years ago part of the building was Hotel California.

So that explains it! Interesting that there were two hotels sharing a building.

Regarding Calle de Maldonado: I did try google maps but nothing rang a bell. I also tried using the street view because there was a small market on Maldonado that you could see looking down on the street from our corner apartment. Years later I was able to go into this same small family market and ask the owner if he knew where the lady I had lived with had moved to...and he did! However, everything looks quite different now and I wasn't able to suss out which place was mine, unfortunately.