As an important center for the hustle and bustle of diplomatic activity between the US and other countries, the State Department has to maintain a splendor unlike any other. Today just the art and antiques part of that splendor is estimated at more than $100 million.

The rooms underwent a massive refurbishment over the years, all fitted with an artificial 18th century backdrop, as well as housing a unique collection of 5,000 historic artifacts. Now, the 42 rooms of the reception area stretch out across 28,000 square feet of space, on the seventh and eighth floors of the State Department’s Harry S Truman Building in downtown Washington’s Foggy Bottom district.

The state of the rooms were unsatisfactory in 1961, and, according to the words of late former curator Clement E. Conger, made the place look “like a 1950s motel”. He wrote that it was “a disaster by any standards for elegant entertaining and international diplomacy”, and got a team together in order to bring together objects dating from early American history – from 1740 under the British Empire, through the 1776 Revolution to 1830. Marcee Craighill, the current curator, explained that the refurbishment was paid through private donations, and today the art and artifacts have an estimated value of $125 million.

Among the prized artifacts is the desk on which the 1783 Treaty of Paris was signed; this famous treaty brought to an end the Revolutionary War in which the colonial states won independence from Britain. It also includes an unfinished sketch for a painting which ought to have commemorated this moment – The five US negotiators, including Benjamin Franklin, are already finished, but the British representative refused to pose for the artist. Craighill noted that the work will soon grace the halls of a French royal palace as part of a temporary exhibition: “Versailles and American Independence”.

Yet, the rooms aren’t especially famous among tourists, with only 20,000 visitors dropping in each year. Diplomatic events and educational programs, though, bring another 100,000 people in annually, and the venue remains popular enough to support its upkeep through private donations. Every year, in August the state rooms are closed for cleaning as a part of their $300,000 annual upkeep.

The décor is definitely important for facilitating discourse between the various diplomatic visitors and the department. It’s based on various famous stately homes, including a reproduction of Thomas Jefferson’s mansion in Monticello, Virginia. The grandest chamber, the Benjamin Franklin State Dining Room, has a 21-foot ceiling and a 98-foot floor rug that weighs 4,000 pounds, under a table that can sit 375 dignitaries. The décor even changes depending on the visitor – in March paintings representing the Niagara Falls were moved to pride of place during a visit by Canadian Prime Minister Justin Trudeau to celebrate “visual highlights of our shared border”.

With such an extensive treatment done to these rooms, they’ll surely continue to play a major role in diplomacy, as well as a great record of the country’s history, for a long time.