Funny you mention Buenos Aires, Donald, because that was my experience there as well. We didn't tour the whole city, but just in the neighborhood where we were staying, there was plenty of stuff to see walking the streets. Some of it in public but a lot of it sort of tucked away. Buenos Aires is about the latitude of Los Angeles, but they get 3 times the rainfall.
Aloe trees were a late discovery for me too, Steve. I remember having my mind blown away by a visit to Rancho Soledad nursery in north San Diego county. Aloe trees are one of their specialties and they grow 'em big (with correspondingly huge price tags, of course). The biggest aloe trees I've seen in person were at the Huntington Gardens in the Los Angeles area. There's also a pretty huge one at the California Cactus Center, close by in Pasadena (another nursery where price would be prohibitive for me).
The one in that person's patio (photo in previous post) does look like it's starting to get big for the space. Hopefully there is no structural issue as a result. I don't think the plant is suffering at all, I just wonder if they knew how big it would get when they planted it. (These things can be deceiving.)
