The Maritime provinces are part of the Appalachian Region of eastern North America. Although there are no great differences in elevation within any of the three provinces, there are a number of diverse landforms as a result of the complex geologic and physiographic development of the region. Most of Nova Scotia is characterized by uplands, and only a few small areas can be classified as lowlands. The entire province was glaciated either by the great continental glacier or by local glaciers. In many areas, the rocky hills were stripped of their soil mantle as the glaciers retreated, while in other areas, rock debris was deposited.

The highest elevations are found in the upland areas that stretch from the Cape Breton Highlands in the northeast to the Cobequid Mountains in the west. The highest point, 532 m (1,745 ft) above sea level, is found in Cape Breton Highlands National Park near the extreme northeastern end of the island. However, the average elevation of the uplands is less than 300 m (1,000 ft), with occasional rounded knobs rising above the general level.

The Cobequid Mountains, which rise to slightly more than 300 m (1,000 ft), appear as a sharp ridge but actually have a plateaulike surface about 140 km (about 90 mi) long. A great inclined sheet of lava forms a sharp steep ridge along the northern coast of Nova Scotia. The ridge, called North Mountain, separates the Annapolis Valley from the Bay of Fundy. The lava sheet dips under the Bay of Fundy so that the sharp edge of the sheet creates a steep slope 150 to 200 m (500 to 700 ft) high.

More than half the area of Nova Scotia lies within the Atlantic Upland. Underlying this region are granites, quartzites, and some slates. The surface of the Atlantic Upland rises from sea level on the Atlantic shore to about 180 to 200 m (about 600 to 700 ft) at the southern side of the Annapolis Valley. The Atlantic Upland, which is cut by lowlands, stretches from the southern tip of the peninsula to Cape Breton Island.

Bordering Northumberland Strait are the Northumberland coastal lowlands, a part of the larger division known as the Gulf of St. Lawrence Plain. These lowlands are underlain by old sedimentary rocks that give the soil a red color in some places. Many of the sediments contain coal.

The most important lowland is the Annapolis Valley, which lies between North Mountain and the Atlantic Upland and is drained by the Annapolis and Cornwallis rivers. The valley is about 130 km (about 80 mi) long and varies in width from 5 to 15 km (3 to 10 mi). The valley developed on weak red sandstones and shales of the Triassic period, about 200 million years ago. The valley’s tidal marshes were the first lands cultivated by European settlers in Canada, and some of the original dikes built to control tidal flooding survive.

East of the Annapolis Valley and extending southward toward the interior of the peninsula is another lowland developed principally on shales and sandstones. The southern half of Cape Breton Island is a region of lowlands underlain by sandstones, limestones, and coal. It is included in the Atlantic Upland region because it is related to it geologically.

The Atlantic shore of Nova Scotia is deeply indented with many small harbors. It is a good example of a drowned coastline, the land having been depressed by the weight of the ice during the last glacial period. Halifax and Lunenburg, centers of the fishing industry, are located on deep inlets on the coast. The tides of the Bay of Fundy are among the highest in the world. The difference between high tide and low tide may be as much as 16 m (53 ft).

Nova Scotia has more than 400 lakes. The largest freshwater lake is Lake Rossignol, at the southern end of the peninsula. Larger than Rossignol is Bras d’Or, which covers nearly one-fourth of Cape Breton Island, and is a saltwater tidal lake linked to the Atlantic Ocean. Rivers are numerous and short, generally less than 80 km (50 mi) long. All have their origins in the Atlantic Upland. The Annapolis, Sissiboo, and Shubenacadie rivers flow into the Bay of Fundy. Among other rivers, the Mersey drains Lake Rossignol, and the Saint Mary’s flows into the Atlantic Ocean east of Halifax.