Washington is like no other American city. It is spacious and low-rise, on a much more human scale than other US conurbations where market forces have been allowed free rein. But its gentle appearance is deceptive; power and danger, interleaved with rich culture and desperate poverty, reside within. The five-square-mile heart of Washington vies with the Vatican as the most influential patch of ground on earth. The president and Congress occupy a ragged diamond, a rough square hewn geometrically from a swamp on the fringes of Maryland and Virginia.

There was nothing much wrong with Philadelphia, the nation's first capital. But in a piece of political skirmishing that preceded the Civil War, the southern states resented a power centre in the north. With arbitrary geometry, a slice of unwanted marshland split by the Potomac River was chosen. The young nation named the land the District of Columbia and built the city of Washington upon it, thus commemorating the European discoverer and the 'father' of America in a single act. From inauspicious origins, Washington has become a giant governmental theme park with a mass of free attractions.

Every planned urban creation, from Brasilia to Milton Keynes, has its problems; Washington's most pressing is the highest murder rate in the US. When the competition includes Los Angeles, Miami and New York this is an awful achievement. The American way of death is a constant theme. Most of those who die by the gun are young blacks, caught up in the vicious drug wars fought out within sight of Capitol Hill. Danger is quantified geographically. Washington is divided into four quadrants; trouble can generally be avoided by sticking to the north-western portion. Panhandlers beg on every street corner, but the biggest risk is cultural burn-out as you tumble through time and space.

To see the best of this loud but lovely capital, look for the people in big hats. Like Yellowstone and Yosemite, much of Washington is designated a national park, and the rangers are out in force. They resemble trainee cowboys or overgrown girl guides, but are invariably friendly and helpful to all the tourists - mostly home grown - roaming around the urban jungle.

From Little Rock and Big Sur the Americans come, to see how their tax dollars are being spent. You, too, will become a taxpayer: George Bush's lips made no promises about not fleecing tourists, and his town imposes an 11 per cent sales tax and dollars 1.50 'occupancy fee' for each night you stay. This itinerary will compensate by showing you the best of the city for no dollars a day. Life is cheap in Washington, but the sights are free.

Day one: Go straight to the top. The tallest structure in the world until the Eiffel Tower was finished, the Washington Monument is still the highest point in Washington. It opens at 9am, at which time the queue is already forming. This marble skyscratcher is a classic obelisk whose height, 555 feet, is exactly 10 times the width of the base. It was begun in 1833 and quickly reached 150 feet, but then the money ran out. For the next 40 years the stump stood forlornly in the middle of America's capital. Mark Twain dismissed it as 'a factory chimney with the top broken off', and spoke of 'tired pigs dozing in the holy calm of its protective shadow'. After the Civil War, Congress voted the money to complete it, and now only tourists rummage around the base.

A queue spirals around the monument; each circuit represents a 45-minute wait. If you can arrange your visit for a weekend, ask to join the 'walk-down' to become one of the few people allowed an inside glimpse of the tower. At 10am and 2pm on Saturdays and Sundays, a park ranger escorts a group down the 897 stairs inside. You pause to admire the plaques placed on the walls.

The tradition began when each of the states was asked to contribute to the monument. Arizona said it could afford only a stone conveying gratitude to George Washington, and this started a trend. All 50 states have supplied messages in local stone; the newest is Alaska's, in solid jade.

When the first lift - a steam hoist - was introduced, women were forbidden to travel in it. They walked, while their menfolk enjoyed food and wine during the 20-minute ride. The current lift takes 90 seconds. At the top is the best view in Washington, although it is impeded by the scratched plastic windows through which you peer, and the hordes of visitors attempting over-ambitious camcorder shots.

Back at street level savour the space. The city looks like one big lawn, the buildings sprinkled thoughtfully in a manner that suggests this is an urban planner's idealised model rather than a real town. A stroll in any direction is impeded only occasionally by streets, themselves used in a gentle manner by drivers who have nothing in common with motorists in Manhattan or Miami. In Washington the pedestrian is king; but the president runs the place.

Work on the White House began 200 years ago. The architect was Irish, the masons were Scottish and the troops that attacked it in 1814 were English. The first occupant, Thomas Jefferson, called it 'big enough for two emperors, one pope and the grand lama'. A century later, President Taft felt it to be 'the loneliest place in the world'. Presumably he had not tried the public tour.

The Kremlin in Moscow is much more accessible than the heart of American democracy. To visit the White House, you must claim a free ticket at the national park office just south of it. You then join a lethargic snake of a queue, covering about 500 yards in the course of an hour.

The first sight you see on reaching the building is a photograph of the five smiling faces, in full unashamed colour, of presidents as far back as Richard Nixon. Things do not improve much. The White House has 132 rooms, but visitors are allowed access to only seven. The place is swarming with the president's men, although the cover of the US Secret Servicemen is easy to spot: not so much from their earpieces through which they receive radio instructions, but from the name badges that announce 'USSS'.

You gaze enviously at the cool and graceful gardens as you are dragged along by the throng. The crowds are thickest at the portrait of Jacqueline Kennedy Onassis in the Vermeil Room. The most handsome chamber is the East Room, where the bodies of Lincoln and Kennedy lay in state after each was assassinated.

Fifteen minutes of peering at fame concludes at the gift shop. It may seem odd that part of the home of the world's most powerful person should be given over to selling souvenirs. But in Washington you soon become used to the concept of postcards being sold in surprising places. In the ultimate consumer society, a frustrated shopper is an unhappy citizen.

Conditions of tenure of the White House are prescribed by the Constitution. This frail document is on show at the National Archives, together with the Declaration of Independence and the Bill of Rights. The atmosphere in their cases is pure helium, the ambience outside is of pure reverence. When the archive is closed all three are lowered 20 feet into a bomb-proof vault.

Along with the paperwork of nationhood there is a soul-searching exhibition of oppression: of Native Americans, slaves, religious minorities. Washington is the nation's conscience, often a guilty one. A 1297 version of the Magna Carta is included, to show where the idea for codifying nationhood began. It was given to the US by one Ross Perot.

The Watergate Tapes receive a lower profile. They are the audio evidence which proved that President Nixon knew of a break-in organised by the Republican Campaign to RE-Elect the President - CREEP. Political burglars crept into Democrat offices in the Watergate building, and political bunglers failed to cover their tracks. The tapes of Nixon's Oval Office meetings proved his downfall. The reels are now housed in a warehouse in the suburbs, and visitors can take a free shuttle bus to savour the undeleted expletives of a world leader in big trouble.

The current president's headache is a Congress dominated by Democrats. America's parliament resides at the Capitol, Washington's most elegant building. Unlike the Palace of Westminster, visitors can wander freely around the seat of Congress, beneath the huge dome that imposes on the Washington skyline. To see a debate in the Senate or the House of Representatives, obtain an International Pass from the crypt. Debates are conducted in surprisingly modest chambers, with senators seated at school-like desks.

Take a moment to look at the mix of people on the streets. Most cities have a blend of business people, factory workers and shop assistants, but Washington appears to be peopled almost exclusively by bureaucrats, tourists and hustlers. Doing lunch in Washington, whether you are a local, a legislator or a sightseer, is easy. An excellent venue is nearby in the old Post Office, a 399ft granite fortress. The innards have been scooped out and replaced with a vast, airy atrium and a dozen places to eat, including Chinese, Indian and Japanese. The free lift to the top reopened last Wednesday, so, after refreshment, a national park ranger will show you the view from the belltower, the second-best vista in Washington.

Judging by the relative queues, most visitors to Washington prefer guns to history. The lines are long at the headquarters of the FBI. The Federal Bureau of Investigation gives out free postcards boasting of its 'Fidelity, Bravery and Integrity'. Its work counters crimes ranging from spying to fraud, but a video starring the bureau's chief, William S Sessions, concentrates on the anti- drug message. Latest figures suggest that the average American spends dollars 750 a year on illegal narcotics. A small display cabinet shows samples of the most popular in a rather too appetising manner. You tour the forensic laboratories where DNA samples are matched and fibres examined. From a single human hair the scientists can determine whether it was pulled or fell out, the owner's gender and age, and what sort of drugs, if any, he or she has taken.

Agents who walk and talk rather like Thunderbirds puppets show you around. They give handy hints on how to tell authentic FBI credentials. Pictures of America's 10 most-wanted fugitives are displayed, and some visitors have recognised faces as those of their neighbours.

The most popular part is the end of the tour - a shooting display with live ammunition. On a firing range behind bullet-proof glass, Special Agent Jeff Holmes shows off his skill with pistols and sub-machine-guns. US citizens aged 23-37 who are fit and hold a driving licence are encouraged to apply for work with the FBI. 'It looks fun, glamorous and exciting,' says Agent Holmes as he reloads, 'and it is.' I asked the marksman with the smoking gun how dangerous he considered Washington. 'Not bad at all,' he replied. On a quiet day only one murder takes place.

The US fashion for assassinating leaders began at Ford's Theatre. During Our American Cousin in 1865, John Wilkes Booth shot Abraham Lincoln, who had led the Union through the Civil War. The theatre itself, and the house across the street where Lincoln died, are open. A chirpy national park ranger regales visitors with details of the US's three other murdered leaders - Garfield, McKinley and Kennedy.

The city centre becomes a void after dark. Bureaucrats are sucked into the depths of the Metro, and whisked off to the safe suburbs. As the homeless select their doorways for the night, visitors need to venture into the urban patches north and west of the White House where people actually live.

A curious feature of Washington's restaurants is that the greatest concentrations are from the world's trouble spots. The best area for dinner is Adams Morgan, on the intersection of 18th Street and Columbia Road, a mile or two north of downtown. The dominant cuisine is Ethiopian, Salvadorean a close second, and Peruvian food is starting to appear.

Day two on Page 40.