There was once a "castle" called Huning castle that was located on Central just east of Old Town many years ago. There are now apartments in its place that are cleverly called "Huning Castle Apartments". I'm a little confused as to why the Huning District was so far away from the actual Huning Castle.
The Huning district is one of my favorite places in Albuquerque. It's downtown just west of I-25 and east of Broadway (I think those are the boundaries) and it's beautiful area with tree lined streets and victorian houses.
If I recall correctly, Franz Huning developed the area when the railroad went in. You see similar types of neighborhoods in Las Vegas, the big railroad town before Albuquerque. I'm guessing that since it was higher up than downtown, it got the name Highland, sort of the original heights.
The Huning Highland Historic district is bordered by I-25 on the East, Broadway on the West, MLK on the North, and Coal on the South (though some say it's Gold on the South). The area was sorta named after the awesome house that was built in the 1890's and torn down (true to Albuquerque's nature) in the 1950's. Check out the house.
Today, the neighborhood is pretty, but has its rough spots. Alas, nothing is perfect. My sister and I lived on High and on Walter when we were in college, and since the 90's the neighborhood has improved. You're centrally located, but there aren't any good grocery stores in the area (the Lowes on Lomas and 12 is singularly yucky, and the Smiths on Yale and Coal is a rich parade of humanity). You can take the Central Rapid Ride or 66 or Lomas 11 bus in no time flat. We could ride our bikes up MLK (then named Grand) to the university. The houses are mostly all built before 1930, and so are not well insulated. There's a bit of a roach problem, but I suspect you might be tidy. So yeah. I would live there if I could afford a home there.
Check out the neighborhood association web page here (ignore the login and click a link on the left) and a blurb from the city of Albuquerque here.
When the railroad was on its way most thought it would go through Old Town. Franz Huning thought different and bought up a lot of land east of current downtown. With the land he sold to the railroad and his subdivision he became a very rich man which enabled him to build Huning Castle. The neighborhood behind where the house stood is called the Huning Castle Addition. Franz named the streets Arno, Edith and Walter after his children.
kreg hill has some nice rentals in hh. some historic, some not. i wouldn't go farther south than coal unless you enjoy pioneering neighborhoods. there good parts south, but sketchy spots too. north of there is pretty well gentrified.