Aotearoa / New Zealand

So, one thing I want is a magnet strong enough to hold up art. But the other thing I want is to not have a kid having their intestines ripped apart (nothing gruesome in that link) if they swallow them. So I've specifically tried to avoid the rare-earth magnets, and instead want a magnet that is strong because it is big and unswallowable. Or at the very least, well attached to some larger structure.