In its simplest sense, “home” means a place of shelter. For most of us, we also want somewhere that makes us feel safe, buffered from the outside world and proud of our little castle. And some people skate off in the other direction, creating their homes to look like works of art.

MSN Real Estate profiled 18 of these unusual houses. Check out the whole list here, but here are some of our favorites:

It may look like a beautiful old manor, but this photo doesn’t do the Winchester Mystery House justice. Built by the heiress to the Winchester rifle company in San Jose, Calif., this house fills up four acres–and that’s a downgrade from when it filled over 160! Added on to over the years, the property has 47 fireplaces and 40 bedrooms.

Yes, this is someone’s home. At one point though, its only occupant was a nuclear warhead. Years of renovations have now made it a livable (and dare we say secure?) residence in central Kansas.

It’s like living in a sculpture! This Mexico City house is called the Nautilus and it’s not only its exterior that interesting–the inside is filled with vegetation and trees.

Yes it’s small, and yes it’s crooked, but what really makes this London house interesting is its (now-sealed) passage to Windsor Castle. Supposedly, it was used as an access point to the castle for a king’s mistress.

Photos courtesy of MSN Real Estate.