UNITED NATIONS >> If you want to take a tour of the United Nations complex, don’t do it during an international crisis.

A public tour of the U.N. routinely includes such stops as the venerable General Assembly Hall, where representatives of the 193 member states meet to discuss global issues, and the Security Council chamber, where the U.N.’s most powerful body meets.

But in the event of high-level meetings scheduled to tackle crises around the world, these chambers and any others may be closed to the public “on very short notice,” according to the U.N. Visitor Centre.

On a recent tour, things were reasonably calm around the world, and visitors were able to see all the main attractions, including the General Assembly chamber. This storied venue looks like it did back in the 1950s, but it now has state-of-the-art electronics, improved heating and air conditioning, and better security, according to the visitor center. A 16-month renovation that ended in 2014 included replacing the gold-leafed background of the prominent U.N. emblem because it was caked with nicotine residue from years of cigarette and cigar smoke. Smoking is no longer allowed inside the U.N., but for a time diplomats could light up here despite a New York City ban, by virtue of it being international territory.

The General Assembly hall was the backdrop for many a memorable moment in diplomatic history. Recalling perhaps the most famous incident, I suppressed the urge to run down to the delegate seats, kick off my shoe and pound it on the table as Soviet Premier Nikita Kruschchev supposedly did when he disrupted a 1960 General Assembly meeting.

The U.N. complex comprises the Conference Building, the General Assembly Building and the Secretariat Building — that’s the iconic 39-story structure with the fluttering flags depicted on film, TV and postcards. Our 45-minute tour began in the Conference Building, where gifts from member states are displayed, including steel drums from Trinidad and Tobago.

Among the factoids our tour guide imparted: Official U.N. languages are English, French, Spanish, Russian, Chinese and Arabic; the world body is in its 71st year; and the national flags outside are displayed from A to Z, from Afghanistan to Zimbabwe. The Security Council includes 15 of the 193 U.N. member states, and five — China, France, Russia, the United Kingdom and the United States — are permanent, which gives them veto power to quash any agenda item.

Inside the Security Council chamber, a mural by Norwegian artist Per Krogh depicts a phoenix rising from a world in ashes, presumably a metaphor for the rebuilding that followed the Holocaust and World War II.

Outside, we viewed the 30 articles of the Universal Declaration of Human Rights, displayed in panels designed by Brazilian artist Octavio Roth, including Article 1: “All human beings are born free and equal in dignity and rights. They are endowed with reason and conscience and should act towards one another in a spirit of brotherhood.”

The Trusteeship Council used to be where colonial issues were discussed, but in a post-colonial world it is used for other events. In 2013 it hosted a youth assembly addressed by Malala Yousafzai, the Pakistani schoolgirl shot in the head by Taliban gunmen for advocating education for girls.

Part of the tour focuses on disarmament. Visitors see objects marred by nuclear explosions in Nagasaki and Hiroshima during World War II as well as exhibits about land mines and the Escopetarra, a guitar made from an AK-47 by Cesar Lopez, a Colombian musician and social activist. Escopetarra translates roughly as “Gun-tar.”

Not on the tour but open to the public anytime is the U.N. garden overlooking the East River. Sculptures here include “Let Us Beat Swords Into Ploughshares,” a bronze statue presented to the U.N. in 1959 by the former Soviet Union depicting a man using a hammer to turn a sword into a plow blade. The concept, from a biblical passage, is a metaphor for ending war and converting tools of destruction into tools for progress. The garden also features a piece of the Berlin Wall.

The number of people who take the tour has fluctuated in recent years, according to the Visitors’ Service Section at the U.N.’s Department of Public Information. That’s mainly because of renovations that closed large parts of the complex to visitors until 2015.

The number has averaged around 200,000 a year for the past five years, and the U.N. is on track to do about 200,000 this year as well. About 65 percent to 70 percent of the visitors are American, according to the department.