The exact geographic center of the United States is near Lebanon, Kansas.

The Chesapeake Bay Bridge-Tunnel - which crossing Chesapeake near its mouth, at Norfolk, Virginia - uses a combination of bridge spans and tunnels. Manmade islands allow the roadway to enter the tunnels beneath the Bay's shipping channels.

The only nation whose name begins with an "A", but doesn't end in an "A" is Afghanistan.

Given their sheer volume, ninety-nine percent of the living space on the planet is found in the oceans. The average depth of the oceans is 2.5 miles (4 km). The deepest point lies in the Mariana Trench, 6.8 miles (10.9 km) down. By way of comparison, Mount Everest is only 5.5 miles (8.8 km) high.

Ninety percent of all volcanic activity occurs in the oceans. In 1993, scientists located the largest known concentration of active volcanoes on the sea floor in the South Pacific. This area, the size of New York state, hosts 1,133 volcanic cones and sea mounts. Two or three could erupt at any moment.

According to NASA, the U.S. has the world's most violent weather. In a typical year, the U.S. can expect some 10,000 violent thunderstorms, 5,000 floods, 1,000 tornadoes and several hurricanes.

Zion, Illinois - located on the shores of Lake Michigan north of Chicago - was founded by the followers of John Alexander Dowie, whose Christian Catholic Church disapproved of pharmacies, doctors, theaters or dance halls. Smoking, drinking and the eating of pork also was prohibited in town.

The U-S Park Service says the older Old Faithful gets, the more the geyser at Yellowstone National Park slows down. In the 1950s, it erupted every 62 minutes. Lately, it's been erupting every 77 minutes. Some experts say Old Faithful may someday just stop.

At 840,000 square miles, Greenland is the largest island in the world. It is 3 times the size of Texas. By comparison Iceland is only 39,800 square miles.

According to experts, large caves tend to "breathe"; they inhale and exhale great quantities of air when the barometric pressure on the surface changes, and air rushes in or out seeking equilibrium.

The surface area of the Earth is 197,000,000 square miles.

Forty six percent of the world's water is in the Pacific Ocean. The Atlantic has 23.9 percent; the Indian, 20.3; the Arctic, 3.7 percent.

The state of Oregon has one city named Sisters and another called Brothers. Sisters got its name from a nearby trio of peaks in the Cascade Mountains known as the Three Sisters. Brothers was named as a counterpart to Sisters.

The Dominican Republic was called Santo Domingo when it first gain independence.

The Chang Jiang river is the fourth longest river in the world.

Bore-hole seismometry indicates that the land in Oklahoma moves up and down 25cm throughout the day, corresponding with the tides. Earth tides are generally about one-third the size of ocean tides.

Ireland currently has the fastest growing economy in Europe - the economy grew by 40% from 1993-1997. It is for this reason that the country is referred to as the Celtic Tiger.

There are more psycho-analysts per capita in Buenos Aires than any other place in the world.

The smallest island with country status is Pitcairn in Polynesia, at just 1.75 sq. miles/4,53 sq. km.

China's largest city is Shanghai.

The U.S. mint in Denver, Colorado is the only mint that marks its pennies.

The original fifty cent piece in Australian decimal currency had around $2.00 worth of silver in it before it was replaced with a less expensive twelve sided coin.

On a trip to the South Sea islands, French painter Paul Gauguin stopped off briefly in Central America, where he worked as a laborer on the Panama Canal.

Guam has seven public elementary schools.

Nepal's flag isn't rectangular. Or square. It's two triangles, sorta.

Newfoundland's time zone is half an hour off of all the others. So are Iran's, bits of India's, Afghanistan's, Burma's, and Nauru's. And some other islands. Like Australia.

The Republic of San Marino is the world's smallest republic (24 sq. miles) and possibly the oldest state in Europe (founded 4th century AD, according to tradition.)

Mount St. Helens dropped 1,313 feet in 1980.

There is a prison in Ossining, New York named "Sing Sing."