What would we do without Frank Frazetta? I like this particular picture because it's not (as far as I can tell) one of his cover paintings for an established figure. The juxtaposition between the Old World knight and the New World visible on Earth is interesting, as is the fact that the moon seems to have a breathable atmosphere. Some sort of alternate-history cosmology, perhaps?
Yeah, that sounds about right. This image I got from a post on What a Horrible Night to Have a Curse . . . , where it illustrated a great idea about a tidally-locked planet that feels like the Land of Faerie in the habitable band - a world of eternal twilight, sandwiched between an endless frozen night and an eternal scorching desert. Since we're doing a sword-and-planet style solar system, this is going to replace either Mars or Venus, and I think the latter works a bit better.
So how are we going to get our premodern heroes off to these strange new worlds? Long-time readers may recall my thoughts about a pulpy dungeon-crawl setting riffing off Stargate, and I think a similar riff works here. This picture gives the gate idea more of a Stonehenge vibe, and the vaguely North American landscape (and the explorer's hat) imply a very interesting Colonial period.
Well, we started this post with a knight, let's end with one, too. Artist Shaun Keenan has a bunch of historical-warriors-riding-dinosaurs pieces scattered across the internet, any one of which could spark a whole campaign idea. What I like about this is that it implies that the gates from Earth to the rest of the solar system are not one-way. Sure, Sir Knight could have picked him up in the twilight jungles of not-Venus, but why not in Africa or the Amazon?
To sum up, then, we have a version of Earth that connects via megalithic portals to other bodies in the solar system that are weirdly different, in a way that encourages exploration. The inhabitants of these other bodies, which include dinosaurs and at least one kind of humanoid monster can also use these portals to visit Earth.
I like it.