Krag's Inaccessable might be possible, afterall

[lajoswinkler]

Not really, because it spins way too fast, but a slower-spinning object could have negative values of G on its equator and still survive intact.

http://www.nature.com/nature/journal/v512/n7513/full/nature13632.html

You couldn't land on it's equator, perhaps not even using harpoons. You might even cause a structural failure of a chunk of it by disturbing the surface.