In the spoiler below is the sketch of the map I have been drawing for my new campaign setting (coastline is black; mountains, red; and hills, yellow). Although I really liked it at first, I have been really unsure lately, and would like to hear some comments.
I was considering connecting it to another landmass (probably via a isthmus) in the Northwest, but it seems to me this could add too much complexity. Let me explain. I don't plan developing this second landmass right now; it would be the foreign, alien land about which none knows much but legends. But with land, ships could easily navigate along the coast and therefore its probable the inhabitants of my main continent (the one in the map below) would have followed that path long ago (technologial level of setting is equivalent to 8th or 9th century, plus low magic). This would demand that I detailed, at least to a certain level, what is to be found there - a work I'm not interested in doing right now. On the other side, I'm a bit unsure of having an Australia-like continent, isolated from everything. It seems to limit my future possibilities.
I'm aiming at a kind of beliavable setting here: if I can't find any reasonable explanation for why my folks would not have sailed that way, I will have to accept they did.
I would like to see what you guys think about these doubts that have been making me unsure. Any critics to the map itself would also be welcome.