(NewsNation) — When federal agents came calling at the home of Donald Trump this week, they were doing so in one of the most storied buildings of the entire Southeast.

Mar-a-Lago is more than a mansion. It’s on the National Register of Historic Places. The 77,000-square-foot estate has 58 bedrooms and 33 bathrooms.

Mar means sea, where the front door faces. And Lago means lake, for Lake Worth.

“It’s immaculate, it’s beautiful. Every room is is a theatrical experience,” said Rose Guerrero, research director at the Historical Society of Palm Beach County.

The opulence was the brainchild of Majorie Merriweather Post, the cereal heiress who spent four years on construction, importing marble, gold and every intricate detail money could buy.

“She wanted it to be very large. In fact, it was Palm Beach’s most elaborate, and most talked about mansion built in the 1920s, for a reason, because it was Marjorie Merriweather Post, the richest woman in the world at that time,” Guerrero said.

Post loved a good party and opened Mar-A-Lago in the ’50s, fundraising for the International Red Cross and giving outsiders a look at the ornamental plaster.

“People today think it’s gaudy. The architects in the past also, and society in the past, potentially thought it was just as gaudy,” Guerrero said.

Throughout the years, renovations have been freshened but not altered.

Former federal prosecutor Bruce Udolff has overseen hundreds of search warrant executions. He told “NewsNation Prime” on Friday that the vastness of Mar-a-Lago made this task like virtually like no other.

“That’s a huge area to have to search. I mean, theoretically, it could be hidden anywhere, on that particular real estate. And they only searched, I think, for four to six hours. So that tells me that they knew what they were looking for. And they had a good idea of where it was,” Udolf said.

NewsNation has also learned that Post left the home to the U.S. government in her will. She wanted it to be a winter White House.

However, it was way too costly, so the government gave it back to the estate. After two sales fell through, Trump bought it for $12 million.