The highest tribunal in the nation, the Supreme Court is charged with deciding whether actions of Congress, the president, the states, and lower courts are in accord with the Constitution, and with applying the Constitution's enduring principles to novel situations and a changing country. The Supreme Court's chief justice and eight associate justices have the power of judicial review -- that is, authority to invalidate legislation or executive action that conflicts with the Constitution. Out of the 7,000 or so cases submitted to it each year, the Supreme Court hears only about 100 cases, many of which deal with issues vital to the nation. The Court's rulings are final, reversible only by another Supreme Court decision, or in some cases, an Act of Congress or a constitutional amendment.

Until 1935, the Supreme Court met in the Capitol. Architect Cass Gilbert designed the stately Corinthian marble palace that houses the Court today. The building was considered rather grandiose by early residents: One justice remarked that he and his colleagues ought to enter such pompous precincts on elephants.

If you're in town when the Court is in session, try to see a case being argued (call tel. 202/479-3211 for details). The Court meets Monday through Wednesday from 10am to noon, and, on occasion, from 1 to 2pm, starting the first Monday in October through late April, alternating in approximately 2-week intervals between "sittings" to hear cases and deliver opinions and "recesses" for consideration of Court business and writing opinions. From mid-May to late June, you can attend brief sessions (about 15 min.) at 10am on Monday, when the justices release orders and opinions. You can find out what cases are on the docket by checking the Washington Post's "Supreme Court Calendar." Arrive at least an hour early -- even earlier for highly publicized cases -- to line up for seats, about 150 of which are allotted to the general public.

There are many rituals here. At 10am, the entrance of the justices is announced by the marshal, and all present rise and remain standing while the justices are seated following the chant: "The Honorable, the Chief Justice and Associate Justices of the Supreme Court of the United States. Oyez! Oyez! Oyez! All persons having business before the Honorable, the Supreme Court of the United States, are admonished to draw near and give their attention, for the Court is now sitting. God save the United States and this Honorable Court!" Unseen by the gallery is the "conference handshake"; following a 19th-century tradition symbolizing a "harmony of aims if not views," each justice shakes hands with each of the other eight when they assemble to go to the bench. The Court has a record before it of prior proceedings and relevant briefs, so each side is allowed only a 30-minute argument.

Call the Supreme Court information line to find out days and times that court arguments will take place. You may view these on a first-come, first-served basis, choosing between the 3-minute line, which ushers visitors in and out of the court every 3 minutes, starting at 10am in the morning and at 1pm in the afternoon; or the "regular" line, which admits visitors who wish to stay for the entire argument, starting at 9:30am and 12:30pm (you should try to arrive about 90 min. ahead of time to snag a spot).

The Supreme Court is cloaked in mystery, purposefully. You can't take cameras or recording devices into the courtroom, and you're not allowed to take notes, either. The justices seldom give speeches and never give press conferences.

When the Court is not in session, you can tour the building and attend a free lecture in the courtroom about Court procedure and the building's architecture. Lectures are given every hour on the half-hour from 9:30am to 3:30pm. After the talk, explore the Great Hall and go down a flight of steps to see the 24-minute film on the workings of the Court. On the same floor is an exhibit highlighting the "History of High Courts Around the World," on display indefinitely. If you tour the building on your own, you should allow about an hour. You might also consider contacting your senator or congressperson -- at least 2 months in advance -- to arrange for a 40-minute guided tour of the building led by a Supreme Court staff member, who will take you places you won't be able to go on your own.

There's also a gift shop and a cafeteria that's open to the public and serves good food.