PENTAGON TOUR GUIDE Jeff Lyons boomed out our marching orders: "When I call your name, step forward for your tour tag."

We put our cameras and other hand-carried items on the conveyor belt and stepped through the metal detector on the concourse that separates outsiders from the inner sanctum of the American military establishment. Formal tours of the building started during the U.S. Bicentennial, and though they're little publicized, more than a million visitors have taken advantage of the opportunity,

Seaman Lyons, 23, a member of the Navy's Ceremonial Guard, led us to a small theater, where a 12-minute film recounts the Pentagon's hurry-up construction. Starting in August 1941, 13,000 men worked round the clock; the military began moving in less than nine months later.

Lyons called us to attention when the movie ended. Time to move out. We entered the Commander-in-Chief corridor, and President Ronald W. Reagan greeted us with a warm smile from his photograph on the wall.

"Does anyone know what President Reagan's middle initial stands for?" our guide asked. Mumbling from the group. "Wilson," a voice called out. "Good," he responded.

Moving past presidential portraits, Lyons continued the Q&A. Which president served longest? Shortest? Who was the youngest? The oldest? The only bachelor? The tallest?

We got the right answers -- not always on the first try -- and headed upstairs to the Air Force art corridor. The eyes of some of the Air Force's finest watched us file past.

"Who was the first man to break the sound barrier?" Lyons asked. The group answered in chorus: "Yeager." A profile of the man with the right stuff was superimposed in a metal bas-relief over the Bell X-1 aircraft he piloted on his historic flight.

We moved on to stand before the likeness of another of the Air Force's heroes. "General Daniel James, better known as Chappie, flew 101 combat missions in Korea. He served 35 years in the Air Force and became the first black officer to receive four stars."

Our next stop was the corridor honoring the Prisoners of War/Missing in Action in Southeast Asia. Eight display cases on the wall listed the names of approximately 2,400 Americans whose fates remain unknown.

An eternal torch dedicated in 1984 glowed above the inscription, "You are not forgotten." We could not take photographs here, Lyons told us, out of respect for these victims of the Vietnam War.

After walking through the Coast Guard and recruiting poster corridors, Lyons halted at the entrance to the Navy-Marine Corps executive area. Its wooden doors with brass name plates, door knockers and room numbers stood out in rich contrast to the more sterile corridors.

"This corridor is modeled after old ship captains' cabin doors," he said, "and is meant to give the feel of being on an old Navy ship."

Handsomely displayed ship and aircraft models also gave the impression of being in a board room area, where at any moment the CEO might appear and frown at all these people wandering about.

Paintings of two of the Navy's most successful former executives occupy the wall space outside the Secretary of the Navy's office. Teddy Roosevelt and his younger cousin, Franklin, both served as assistant secretaries on their way to the White House.

The tour next maneuvered into the Army's executive area. Known as the Marshall Corridor, it resembled the Navy's, and is named for Gen. George Marshall, a graduate of Virginia Military Institute.

Details of Marshall's accomplishments filled the displays along the corrridor: service in World Wars I and II; Secretary of State and architect of the European Recovery Program (the Marshall Plan); president of the American Red Cross; Secretary of Defense during the Korean War, and recipient of the Nobel Peace Prize in 1953, the only career soldier so honored.

The tour entered the Hall of Heroes, which memorializes more than 4,000 Medal of Honor recipients. Three large replicas of the award hang on the wall above cases displaying the real medals -- one for Army service, another for Air Force, and the third for the sea services.

Lyons quizzed us again: "Who was our most decorated soldier?" "Audie Murphy," the group shot back. "He received every medal for which he was eligible," said Lyons, "except one: the Good Conduct Medal. He was very homesick and went AWOL four times while in the service."

The tour ended with a trip through the corridors honoring Military Women and State and Territorial Flags. Lyons related the story of Rear Adm. Grace Hopper's long naval career, spanning four decades, and her role in developing the computer language COBOL, which earned her the title "grand old lady of software."

In the flag corridor, we learned that the Rattlesnake Flag/First Navy Jack almost became our national banner but missed approval by one vote in the Continental Congress. Beneath the serpent on its red and white striped background, a young nation boldly issued the warning: Don't Tread On Me.

FIVE-SIDED TRIVIA

Pentagon construction started in August 1941 on a site of an abandoned airport, wasteland, swamps and dumps. The projected completion was in 1945; Japan's attack on Pearl Harbor changed that timetable.

Working three shifts around the clock, 13,000 workers had the first spaces ready for occupancy on April 29, 1942, and the building was completed by the following January 15, at a cost of $49.6 million. Total expenditure for the project including outside facilities was $83 million. The Pentagon never had a formal dedication because there was a war on.

Covering 29 acres, the Pentagon's 6,546,360 square feet of floor area is three times that of the Empire State Building. The Capitol could be placed inside one of its five sections. The Washington Monument, lying on its side, would stretch from an exterior wall to the middle of the five-acre courtyard in the building's center.

A pamphlet describing the Pentagon states that "despite the 17 1/2 miles of corridors, it takes only seven minutes to walk between any two points in the building."

Some additional statistics on the Pentagon: 23,000 employees can choose from two restaurants, six cafeterias, nine beverage bars or an outdoor snack bar (open spring and summer); check the time on 4,200 clocks; drink from 685 water fountains and use 150 stairways and 19 escalators.

With shops in its concourse area and a post office, the Pentagon does nicely as a small city.

TAKING A TOUR

Tours are available on any governmental work day at 9:30, 10, 11, 11:30 a.m., noon, 12:30, 1, 2, 2:30 and 3:30 p.m. until May 1, when summer tour times go into effect. Children under 10 may take the tour when accompanied by an adult; those over 10 may sign up for the tour themselves, but proper behavior is enforced.

Take Metrorail (Blue or Yellow lines) or bus to get to the Pentagon. As you leave the escalator from the Pentagon Metrorail stop, look for the tour office in the concourse area. Visitors using wheelchairs can participate in tours if arrangements for motorized carts are made 48 hours in advance through the tour office (695-1776).

Cameras and tape recorders are permitted on the tour, but no photographs can be taken of open offices and in the POW/MIA corridor, and no flash photos of old recruiting posters are allowed (flash dulls the finish).