As I mentioned initially, the focus of this campaign setting will be one of four main continents that occupy this world. This continent consists of coastal regions along the western, southern and eastern regions which are separated from the inner main continent by long mountain ranges that are mostly impassable.
Quick continent sketch
The inner continent inside the mountain ranges is 3500-4500 feet above the coastal regions. There are a number of passages through the mountains, though most of them are typically snowed in or otherwise impassable most of the year.
There are several river valleys that pass through the mountain ranges from the inner plains to the coastal regions. Most of these, however, are not easily traversed. They have numerous narrow passages and high waterfalls. There are few who brave these routes, even in the dry seasons.
Along many of those rivers are quite a few lakes. There are also 4 inland seas. Three of them are in the inner plains. The fourth is in the center of the southern coastal region.
Little is known about the inner region of the continent. There are vast regions of rolling plains and flat lands. Not much is known about the inner regions now. While it was once inhabited, a great catastrophe befell the continent and most of the inner continent was decimated. Few who venture into the inner region now ever return. Those who do bring wild tales of strange beings, nomadic tribes and ruined cities. A few have told of a massive mountain that sits near the center somewhere, but none who speak of it have gone anywhere near it.
The northern edges of the continent are tundra wasteland and the temperature remains below freezing all year round. They are sparsely populated by strange nomadic tribes who have little interaction with anyone else.
There are a number of large islands off the eastern and western coasts. Once part of the main continent itself, they were separated out during the great catastrophe. Some are a part of a mainland nation while others are their own kingdoms. Many of the islands are inhabited, though a few have been left wild or allowed to return to a wild state.
The eastern and western coastal regions are mostly temperate in nature, though each has a minor desert/arid area. Forests are common and vast between the regions of farmland surrounding the cities. Animal life is plentiful and both hunting and farming are common ways of life.
The southern coastal region is more jungle and tropical in nature. Farming is much less common. The inhabitants rely mostly on hunting, fishing, or trade with the other nations.
Due to the great catastrophe, there are still quite a few ruins to be found in the coastal regions and the islands. These will be more likely to be lower challenge rating in nature. This is due to being located in easier to reach areas that have been patrolled by government authorities. Inner region ruins and locales are much higher in challenge rating, having been long abandoned and unexplored by anyone. The southern coastal region is host to ruins and dungeons of all levels due to much of it still being wild jungle areas.