Cape Breton's Cabot Trail (Nova Scotia): This 300km (185-mile) loop through the uplands of Cape Breton Highlands National Park is one of the world's great excursions. You'll see Acadian fishing ports, pristine valleys, and some of the most picturesque coastline anywhere.
Along Cobequid Bay (Nova Scotia): When it comes to scenery, Cobequid Bay (near Truro) is one of the region's better-kept secrets. The bay is flanked by two roads: Route 2 runs from Parrsboro to Truro; Route 215 from South Maitland to Brooklyn. Take the time to savor the rocky cliffs, muddy flats, and rust-colored bays.
Fundy Trail Parkway (New Brunswick): East of Saint John, you'll find this 11km (7-mile) parkway winding along the contours of the coast. Get out and stretch your legs at any of the 22 lookouts along the way for fantastic cliff-side views. Or if the tides are out, clamber down to one of the stretches of sand nestled between the rocks.
Prince Edward Island National Park: Much of the north-central shore of PEI is part of the national park, and a quiet park road tracks along the henna-tinted cliffs and grass-covered dunes. There's no single road, but several shorter segments; all are worth a leisurely drive, with frequent stops to explore the beaches and walkways.
Viking Trail (Newfoundland): Travelers looking to leave the crowds behind needn't look any further. This beautiful drive to Newfoundland's northern tip is wild and solitary, with views of bizarre geology and a wind-raked coast. And you'll end up at one of the world's great historic sites -- L'Anse aux Meadows.