Niagara Falls. Three of them actually and located on the Niagara River which drains Lake Erie into Lake Ontario. Averaging about 4 million cubic feet of water per minute. Man, that's a lot of water.
Outer Banks. A 200 mile ribbon of sand beginning in the southeastern corner of Virginia Beach and stretching southward to form narrow barrier islands off the coast of North Carolina.
Hawaii Volcanoes National Park. Encompasses two active volcanoes: Kilauea, one of the world's most active volcanoes, and Mauna Loa, the world's most massive volcano.
Maine Tides. Especially in Cobscook Bay, notorious for ripping tides and powerful currents. The surges cause a rare phenomenon: reversing falls. Near Pembroke, the rapids that course over the rocky bottom actually reverse direction with the tide. Boulders on the bottom, along with the narrow passageway between the shores of the mainland and Falls Island, form a bottleneck that causes a rise in the depth of water on the near side of the falls. The tide rise up to 21 feet every 6 hours!! That's 21 feet up and down ...
Grand Canyon. A steep-sided canyon carved by the Colorado River in Arizona. It's is 277 miles long, up to 18 miles wide, and attains a depth of 6,000 feet.
Bonneville Salt Flats. A densely-packed salt pan in northwestern Utah that is a remnant of the Pleistocene Lake Bonneville. It's at its most impressive if you enter from the west, descending from the mountains on I-80.
Mount Rainier. The highest mountain in Washington and the Cascade Range at 14,411 feet. On clear days it dominates the southeastern horizon in most of the Seattle-Tacoma area. On days of exceptional clarity, it can also be seen from as far away as Portland, Oregon, and Victoria, British Columbia. It's also one of the most dangerous volcanoes in the world.
Bridalveil Falls. 617 feet of water cascading into the Yosemite Valley - although in the dry season or when it's windy, the water doesn't always reach the ground.
Natural Bridge. A Virginia geological formation in which Cedar Creek has carved out a gorge in the mountainous limestone terrain, forming an arch 215 feet high with a span of 90 feet. Once owned by Jefferson and surveyed by Washington.
Old Faithful. A cone geyser in Yellowstone National Park, Wyoming. Eruptions occur about every 90 minutes today and can shoot as much as 8,400 gallons of boiling water to a height of 185 feet. These eruptions can last as long as 5 minutes.
Hubbard Glacier. A tidewater glacier in Alaska, it stretches for 76 miles.
Great Salt Lake. So cool - just outside Salt Lake City, of course, but even cooler if you swim in it. Depending on its level, it's up to 8 times as salty as the ocean. Go soon - it's shrinking.
Barringer Crater. Created 50,000 years ago east of Flafstaff, Arizona by a nickel-iron meteorite about 50 meters across that impacted at a speed of several kilometers per second. Rim to rim - 3/4 mile.
Redwood Forests. Along the northern California coast - tall trees, really tall trees. The tallest in the park is "Hyperion" at 380 feet.
Monument Valley. A region of the Colorado Plateau characterized by a cluster of vast sandstone buttes, the largest reaching 1,000 feet above the valley floor. Near the Four Corners area.
Two Ocean Pass. Wyoming. The only place in the country where a tributary breaks off into two directions – one towards the Pacific Ocean and the other towards the Gulf of Mexico and the Atlantic Ocean. If a fish were to follow this path, he could swim from one side of the country to the other. He'd be tired, but he could do it.
Then there are all the places that are hard to ... well ... place. The Mississippi River, The Smoky Mountains, The Great Plains, The Everglades, The Badlands, etc.
I have to admit I have made it to only about half of these, but there is time. And I've got just the car for sightseeing. Vrooom!!!
What a country! Who's up for a road trip?