Gilligan wrote:
http://www.dailymail.co.uk/pages/liv...n_page_id=1770

I think that parts of Mars look very much like Karst areas (this means
caves) so I tell my kids that some day they will be able to explore
caves on Mars. My 9 yr old daughter told me last time we went caving,
"Daddy, I wont like it when the rocket goes so fast because it might
explode". However, she was up for exploring caves there. I might be
young enough to explore lava tubes on the moon when we finally get back
there but the martian caves will have to wait for my kids.