Brandy Snow competes in the new season of "The Amazing Race"

Have you ever downed a shot of vodka off the blade of a saber in Russia? Or found a real-life "Girl From Ipanema" on a beach in Brazil? How about building a snowman in the 120-degree heat of Dubai?

Contestants on "The Amazing Race" have done all three -- and faced myriad other intense challenges over the show's 15 seasons -- and are now doing even more in this, the 16th round.

The nearly 4,000-mile journey across five continents and eight countries began on Feb. 14 when the 11 teams departed from Los Angeles and had to start the trip by navigating their way to LAX relying solely on public transportation for the first time in the show's history -- no easy feat to begin with.

This season, contestants will be retracing the early-career steps of rock icons The Beatles, participating in a demanding reenactment of the First World War in France and will run into "one of the world's most infamous villains," according to a CBS news release.

Season 16 features teams of all kinds, including couples, parents, siblings, friends, models, lawyers and even cowboys.

Among the participants is the show's oldest-ever competitor, Jody Kelly, a 71-year-old personal trainer who's teamed up with her granddaughter. As well, this season features the show's youngest-ever competitor (excluding family editions), Caite Upton, a model and actress from Lexington, S.C., who is paired with her model-and-actor boyfriend, Brent Horne. They will be competing against, among others, a pair of police detectives, Louis Stravato and Michael Naylor from Providence, R.I., and a father-daughter team made up of World Series champion baseball coach Steve Smith and his daughter Allie.

Legend has it that the idea for the show was spawned by a bet made between show creators -- and now executive producers -- Bertrand van Munster and Elise Doganieri. At a trade convention, Van Munster had challenged Duganieri to come up with a TV-show concept in less than five minutes. She proposed a reality-show race around the world. The two polished the idea, sold it to CBS and the rest is history.

During its first four seasons, the show garnered ample critical acclaim but faced less-than-stellar ratings, sitting on the cusp of cancellation many times.

Producers and network execs blamed the show's troubles on the fact that the series premiere aired six days before the Sept. 11, 2001, terror attacks, and by the time viewers were ready to watch, "The Amazing Race" was lost among all of the other reality shows that had cropped up, not the least threatening being the reality-ratings juggernaut "Survivor."

The series has done increasingly well over its nine-year run, with the last edition's season finale garnering the show's highest ratings of that season and coming in second overall in that night's ratings.

It's never had trouble in the critical department, though. "The Amazing Race" has won seven prime-time Emmys for Outstanding Reality Competition Program, taking the prize every year since the category was created in 2003 and beating out all of the other reality giants, such as "Survivor" and "American Idol," each time.

The show has also won a handful of Creative Arts Emmys for editing and cinematography. Host Phil Keoghan was nominated for a 2009 Emmy for Outstanding Host for a Reality or Reality-Competition Program, but lost out to "Survivor" host Jeff Probst.

For Keoghan, though, that award would have been simply a blip on the radar compared to the amazing things he's done in his lifetime.

After a near-death experience at age 19, Keoghan became determined to live his life to the fullest and has since come pretty darn close. He's broken a world record for bungee jumping, dove through the world's longest underwater cave, and renewed his wedding vows to wife Louise underwater while feeding sharks.

In the spring of 2009, he organized a bike ride across America to raise money for multiple sclerosis research. He keeps an ever-evolving "list-for-life" of the things he'd like to accomplish in his lifetime. Currently on that list are things such as being a ball boy at the U.S. Open, climbing Mount Everest, traveling into outer space, and putting a golf ball across the entire country of Scotland.

This season's premiere marked CBS's launch of a Sunday night two-hour reality block, with "The Amazing Race" being preceded by the network's latest reality venture, "Undercover Boss."

That new series covers high-level company executives who disguise themselves as low-ranking employees to examine the workings of their companies. It premiered on Feb. 7, following the network's coverage of Super Bowl XLIV, and has now settled into its regular time period before "The Amazing Race."