Dreadmire is surrounded by freshwater marshes, wet prairies, soggy savannahs, marshy ponds dominated by giant cutgrass, pickerelweed, green arrow arum, giant plume grass and spider-lilies — prime habitats for alligators and insect larvae. These moist expanses have lots of grasses, sedges and other plants maintained by frequent, natural fires. Around these marshlands are peat-filled tree bays, waterlogged copses up to five miles wide, containing standing water for most of the year. On the southwest side of the tree bays, within the floodplain, are several hardwood bottomland forests, where stately oaks, hickories, cottonwoods and sycamores tower over a sparse understory of flowering herbaceous plants, vines, woody shrubs, ashes and maples.
Cutting through the center of Dreadmire are two rivers that merge: the slow-moving (1 mph) Fowl River that slogs east to west, and the muddy Meander River that flows (3 mph) north to south. These wide (Meander reaches up to 35 miles wide, and up to 200 ft. deep; Fowl up to 15 miles wide, 75 ft. deep), alluvial rivers move their sluggish waters to the sea, carrying rich organic matter, along with fish and invertebrates, into the floodplain swamp from two sides. Both rivers are aggrading, having formed scores of oxbow lakes and loess sheets along their ancient pathways amidst dangerous currents.
Fowl River feeds from the intense runoff of large mountain range to the west, an area dotted with ephemeral ponds and streams. The larger streams can be traced back to the mountaintops where the lively waterways roll and tumble over rock-strewn bottoms, forming gorges, waterfalls and scenic pools throughout the Highland Forest of mature oak, hickory and pine. Animals such as black bears, shrews and flying squirrels occasionally migrate to the swamps below in search of food or warmer climate. The Jagged Forest, the highest area of the mountains, is occupied by mountain and hill giants, using Fraser firs and red spruce trees for kindling and shelter.
The head of the Meander River is beyond the scope of this supplement, lying over 3,000 miles to the north, and carrying ship traffic through hills and farmlands downriver. At the outlet of the Meander River are bays that allow sea creatures access to the swamp. Brackish estuaries that form here are spawning grounds for an impressive array of seafood, including blue crabs, striped bass, shrimp, oysters and bluefish. Beyond this is Cay Bay, bordered by marsh periwinkles that are habitat to mollusks, crustaceans, insect larvae, and fishes ranging from spotted sea trout to pinfish. Away from the river flow, the coastline is a spotty mixture of salt marshes, tidal mudflats, maritime forests of mangroves, and sandy beaches of windswept yardangs protected by barrier islands.
The mountains to the west hold sophisticated tribes of crag-dwelling tribesfolk, as well as cliff-dwelling Neanderthals. These high peaks stop abruptly at the edge of the swamp, crumbling into sharp drops above steep cliff faces. The local mountain dwarves operate a dozen or so copper and ruby mines below Caldera Swamp, which winds through crumbling calderas (a clan of these dwarves was forced to flee into the swamp many years ago, now living there as the Mud Dwarves). Most of the smaller adjacent volcanoes have long since collapsed and flooded, forming a series of caldera lakes called The Cauldrons. Inside one of the two remaining cones is the Underground Forest, its 23,000 foot deep floor lined with lush vegetation, including mobile carnivorous plants (as well as dire animals and a multitude of dinosaurs). The other remaining cone has no surface vegetation of any kind, and is effectively a desert of obsidian rocks and deep ash. This Obsidian Desert is controlled by three warring tribes, two lamia tribes, and a tribe of red-skinned humans guided by a lammasu.
Native human Hill Clans also live within the hills near the swamp edge, as do curious gnomes. The hills themselves are immense where they begin across the gap between the mountains and the hilly regions, decreasing to rolling hills as they approach the swamp and dry flatlands. The territories of the surrounding countries are filled with ranchland, farmland, and deciduous forests. The western edge of the mountains and hills is the Paludial Sea, a shallow sea that stretches for hundreds of miles.
A broken and rocky salt expanse extends for many miles at the east end of the swamp, separated by the Lorgrave Mountains. The Great Salt Swamp is at the center of the largest salt flat in the world (6,400 sq. miles). The desert is the remnant of Lagu Minin, an inland sea that evaporated after the last ice age. Orc salt harvesters are frequent visitors, and dwarven salt miners are residents. The area is plagued by bulettes, gnolls, harpies, lamias and salt ghouls that roam the broken plain, preying on the human remnants of a sea nation destroyed by the loss of the inland water. There is a lammasu that lives in salt-encrusted ruins of displaced sea elves, and a sphinx is known to live along the mountain range that was once a series of islands in the sea. If properly coaxed, the sphinx tells of a salt demon controlled by a witch-queen, Salina, that keeps factions of the Natronese tribes warring with each other. The Great Salt Swamp is a collection of playa marshes, shrub swamps, salt pools, scrub swamps, and mangrove swamps separated by rolling salt dunes. The natives avoid the place, citing "walking trees" as the reason, which may refer to the mangrove treants known to live there.
For those that wish to explore lands far away, the planet of Silur [its proper name is Silur Unas, which means “one tribe” in the Aboriginine tongue] possesses four great continents, Baltica, Gondwana, Laurentia, and Nuberia; there are also two continental fragments, Avalonia and Armorica; and eight microcontinents, Albiga, Cardiff, Esox, Llanelli, Merovech, Rhyl, Sion, and Tethys. The vast Panthallassic Ocean occupies nearly half of the Silurian’s world, dotted with thousands of islands, and a vast shallow area known as the Forgotten Sea (thought to entirely cover a fifth great continent). The two smaller oceans of Iapetus and Rheic are sandwiched between the four great continents. Laurentia is predominantly covered by the Paludial Sea, a body of shallow water that runs nearly through it’s enter length, dotted by the Island Mountains. Dreadmire Swamp is but a small bit of land on the tip of South Laurentia, set between the Paludial Sea and the Panthallassic Ocean.
Beyond the Ophel Highlands and Agnathan Mountains to the east, lies the Sea of Mud, a vast mudflat that borders the Paludial Sea. The North Pole is bitter cold, as would be expected, but oddly the South Pole is even hotter than the equator. Silur Unas is orbited by two large moons, Ealune and Daelune, which in turn are orbited by seven smaller satellites, Cavus, Fossa, Mercan, Narsus, Regolith, Tribol, and Umbraphilia; all of which orbit the sun, Easol. A dark sister planet, Macula, is said to also orbit the sun very near Silur, as well as a score of planets, planetesimals, and protoplanets orbiting much farther away.