In Earthsea islands are large and numerous, in Lord of the Rings, on the other hand, islands barely appear and are small. In both cases they are locations and destinations and themselves contain terrain.
In Tolkien’s wider work, Númenor is the most notable island – a version of Atlantis, which itself gives us a classic inspiration for islands in Western literature. Oceanic islands can be countries with their own terrain but cut off from surroundings. Le Guin depicts the islands of Earthsea more like medieval era city-states with a wider common culture but no central authority.
It is interesting to me that Tolkien, who draws on many aspects of Britain and Britishness in building Middle Earth, avoids the island quality of Britain. This despite a tendency to mythologize the insular quality of Britain in English propaganda-history both in high-culture (Shakespeare’s ‘sceptered isle’) and low-culture (‘fog in the channel, continent cut off’). George R.R. Martin’s Westeros does this by having it be an eratz England circa the War of the Roses (with Scotland being another place full of ice zombies). Westeros’s scale seems flexible but it’s primary plot role as an island is to be a container. Events are within Westeros (up to the Wall) or beyond (either over the wall or on another continent).
The point being – oceanic islands are treated as political units rather than as terrain.
Really big lakes are no different than seas, so I’ll assume we aren’t talking about really big lakes. Tolkien puts islands and towns in lakes, Wolfe puts floating reed islands in a lake and lakes in general distinguish themselves from rivers plot wise by what they might contain.
Small lakes (and pools) maybe places of magic or sacredness. In Stephen Donaldson’s Covenant books, Glimmermere is a magical lake that even gets a magic sword thrown in it and later retrieved.
Small Islands (and other things, in lakes and rivers)
Laketown in The Hobbit is not quiet an island as such but effectively it is and rather like big islands, we have an island as a kind of political entity. People live on and next to lakes, so it makes sense to have islands in lakes as communities. Which in turn makes islands on which people don’t live somewhat mysterious. Deserted islands are spooky in the way a deserted structure is spooky.
Flipping back to island’s in oceans, A Wizard of Earthsea includes a section on an island so small that it is little more than a sandbar. There Ged encounters two castaways with a mysterious past which goes unresolved in that book but which provides a bridge to the sequel.
Swamps have a dual nature. Death and decay on the one hand and overly fecund on the other. The Dead Marshes in Lord of the Rings, literally contains dead bodies whereas other swamps and marshes and mangrove-like environments can contain an excess of insect life or harbor unusual creatures (e.g. the rodents of unusual size in the Fire Swamps of the Princess Bride).
Like forests, swamps are places where navigation is difficult and in which becoming lost is an active danger.
Wastes, wilderness, deserts and ’empty’ lands
The notion of wilderness is a politically charged one. The notion of land that cannot be settled and hence is empty is, to but it bluntly, a colonial lie. If it isn’t Antarctica, then people live there, if less densely than other places. However, the idea as a part of a fictional territory continues. Wilderness is empty AND the people who live there are dangerous AND it is a frontier.
To see the contradictions consider Tatooine. It is a desert, it is empty and yet it is where the Sand People (and Jawas I assume) live. Luke lives on what is a frontier farm that echoes Western settlement of empty-not-actually-empty lands in North America and Australia.
Like swamps and forests, wastelands are places in which becoming lost is an ever present danger. Exotic creatures may live in the desert but unlike swamps and forests the desert (or snowy wastes) are characterized by a lack of life. What joins old growth forest, swamps, deserts, and snowy wastes together as threatening places in which survival is at risk is they are not managed land (again in reality even this may not be true).
Swamps, sandy deserts and snowy wastes share a common feature that other wastelands do not necessarily share: the ground itself is treacherous and you may become pulled below it. Quicksand, mud, a crevasse covered by snow or sand all are dangers that subvert the idea of solid ground.
Journeys through the wastes are wearisome and psychologically and physically tiring for characters. Again, assuming the default for classic fantasy of European like people from towns or from farmed land. As such, the wastes are like the ocean and characters may survive by encountering people who know how to live in this different environment.
In The Farthest Shore, Le Guin uses an encounter like this using the open ocean outside of the archipelago as a kind of virtual desert for Ged – who, despite being from a sea-faring culture is beyond the terrain in which he can live.
I’m intentionally trying to avoid talking too much about ethnic stereotypes in fantasy literature with regard to terrain in these posts. Too big an issue to address properly at this point and better served with its own discussion. Much harder to avoid with sandy deserts as Western Orientalism brings its own baggage along to deserts and desert societies.
Speaking of which…jungles. Forests but with swamp elements. Wet and fecund and dangerous and exotic. Again loaded with colonial baggage and assumptions about both emptiness, ‘untamed’ nature and ‘savagery’.