On Wed, 10 Mar 2004, Buck Galaxy wrote:

About four kilometers to the SE, in the Columbia Hills, is what looks
like it could be a gigantic cave. Check out this huge image:

http://www.msss.com/mars_images/moc/...1301467.25.gif

Be sure to click to maximize the image. It could be shadow but I
don't think so. It looks like it might have been an impact into the
side of the hill. This looks like a very good end mission goal.
Although a solar powered rover might not feel too welcome in a cave.

Thanks for these references. However as this 4.5 meg .gif file is beyond
my meager resources, is there a .jpg version or a much smaller .gif?