The third season of the British period drama “Downton Abbey” comes to a close on PBS Sunday night, and, in celebration of the beloved show, we’ve compiled five interesting tidbits of trivia to prepare you for the season finale.

Maggie Smith Has Never Watched “Downton Abbey”

In an interview with Steve Kroft of CBS “60 Minutes,” Maggie Smith, who plays the fierce elderly matriarch Violet Crawley, dowager countess of Grantham, acknowledged she has never seen the show, despite her starring role in it. During the interview, airing Sunday, Smith said she’s too much of a perfectionist to actually watch herself on-screen.

“It’s frustrating. I always see things I would do differently and think, ‘Oh, why in the name of God did I do that?’” Smith said.

The 78-year-old actress -- who has won three Emmy Awards, two Oscars, and a Tony -- also said that her acting style can scare many of her co-workers.

“You’re trying to say that I am what everybody says ... I’m scary -- and I understand totally,” Smith said. “Old people are scary, and I have to face it, I am old, and I am scary, and I am very sorry about it, but I don’t know what you do.”

“Downton Abbey Is Filmed Inside A Real Castle

It’s obvious that many of the show’s exterior shots are set outside a real castle, but, for the most part, its interior scenes are filmed in the same location. “Downton Abbey” is shot almost entirely in and around Highclere Castle in Hampshire, England, as noted by IMDB.

With the exception of scenes depicting the kitchen and servants’ quarters, every shot inside the Crawleys’ home is actually filmed inside Highclere Castle. The show’s producers wanted to film “Downton Abbey” entirely in Highclere Castle, but the kitchen and servants’ quarters have been too modernized to look authentic. As a result, kitchen scenes are filmed at Ealing Studios in West London.

Highclere Castle also isn’t the only castle to make an appearance on “Downton Abbey.” Other castles featured on the show include Iveraray Castle in Argyll, Scotland, and Lincoln Castle in Lincolnshire, England.

“Downton Abbey” Holds A Guinness World Record

“Downton Abbey” is the world’s most critically acclaimed TV show, Deadline reported, citing Guinness World Records. Its first season earned a 92 out of 100 on Metacritic, dethroning previous record-holders “Mad Men,” “Modern Family,” and “Sons of Anarchy.”

“Downton Abbey” is also most frequently nominated British television series in the history of the Emmy Awards. At the Emmy Awards presentation last year, the series picked up a shocking 16 nominations -- although it won only one.

No One Knows How To Spell “Downton”

“Downton Abbey” may be universally beloved, but that still hasn’t stopped people worldwide from calling the show “Downtown Abbey.” 

A Google search for “Downton Abbey” brings about 140 million results, while a similar search for “Downtown Abbey” returns only slightly fewer, around 110 million. The search-engine results show that media outlets such as the Huffington Post and Newsday have published articles with the show’s name misspelled There's even a Facebook fan page for people who love the show, but can’t be bothered to get its spelling right.

Agent Scully Almost Played Lady Grantham

Gillian Anderson, who starred in “The X-Files,” told TV Guide last year that she was offered the role of Lord Grantham’s American wife, Cora Crawley, countess of Grantham, in “Downton Abbey.”

Anderson was discussing her role as Miss Havisham in a BBC adaptation of “Great Expectations” when she mentioned that she was offered the part. “Hopefully people will embrace ['Great Expectations'] with the same love that flowed toward 'Downton Abbey.' I was actually offered a part in 'Downton,’” Anderson said. 

Ultimately, the role went to Elizabeth McGovern. It might have been for the best, too, because McGovern has consistently delivered standout performances throughout the show.