According to The Washington Post, there are more museums scattered across the United States than there are Starbucks and McDonalds combined — an estimated 35,000 such institutions ranging from grand and important to obscure and offbeat.

It is the latter category, hosting collections ranging from weird to wonderful, that most evoked our curiosity. Here are eight of our favorite offbeat U.S. museums.

The Mob Museum in Las Vegas, Nevada

Las Vegas tends to romanticize its early links to mafia figures such as Benjamin "Bugsy" Siegel, Sam Giancana and Anthony Spilotro. But the Mob Museum (whose actual name is the National Museum of Organized Crime & Law Enforcement) takes a more educational approach with the intention of advancing public understanding of organized crime and its impact on American society.

It does this effectively, using an array of state-of-the-art interactive exhibits, themed environments and authentic artifacts. Among the fascinating displays to be seen here are the actual wall against which six of Bugs Moran's men were slain in Chicago's 1929 St. Valentine's Massacre, the barber chair in which the infamous Albert Anastasia was whacked and an electric chair.

Slip on some headphones and you can listen to FBI wiretaps used to gain evidence on mobsters.

Contact: 702-229-2734 or visit TheMobMuseum.org.

National Mustard Museum in Middleton, Wisconsin

When his beloved Boston Red Sox lost the World Series in 1986, Barry Levenson was terribly depressed. To help distract from the loss, he did what any good BoSox fan would do — he started collecting mustard. This is a true story.

After a few few years Levenson had mustered so much mustard that he had no choice but to open a museum to display it all along with a store to sell the popular condiment. Subsequently Levenson's National Mustard Museum has amassed a collection of 5,676 mustards from all 50 states and 70 countries plus a huge assemblage of mustard pots, antique tins and vintage advertisements.

This improbable museum has become a shining temple to the "King of Condiments" and ranks as one of Wisconsin's most popular attractions. It has been featured on the Oprah Winfrey show and other national TV and radio shows and plays host to the World-Wide Mustard Competition.

Contact: 800-438-6878 or visit MustardMuseum.com.

Ripley's Believe It or Not! Odditorium in Orlando, Florida

For more than 90 years, Ripley's has been at the forefront of entertaining visitors with the odd and unusual, displayed at 80 facilities around the world, including more than two dozen in the U.S.

The Orlando Odditorium may be the best of them all for viewing a wide-ranging collection of barely believable oddities. The weirdness begins as you approach the building, which appears to be sliding into a giant sinkhole.

Once inside, you'll be caught up in a web of intriguing exhibits, including a collection of shrunken heads, a two-headed calf, a six-toed pig and a full-scale mannequin of 8-foot, 11-inch Robert Wardlow, the world's tallest man.

The Odditorium features a number of man-made oddities as well, the most interesting being a three-quarter scale model of a 1908 Rolls Royce constructed from more than a million matchsticks.

Contact: 407-345-8010 or visit Ripleys.com/Orlando.

Ringling Circus Museum in Sarasota, Florida

Yet another incredible Florida museum, this one is fittingly located on the estate of the late circus magnate John Ringling. Nowhere else will you see anything like the museum's amazing miniature recreation of a circus.

It was built in extraordinary detail to a scale of 3/4-inch to the foot by one man, Howard Tibbals, who created the exhibit over a period of more than 50 years. The display depicts a Ringling Brothers' Circus as it would have been set up during the heyday of the traveling circus in America.

There's a Big Top (containing 7,000 mini-sized folding chairs) flanked by 55 miniature train cars and surrounded by wagons, sideshows and food stands. Tibbals' panoramic presentation covers an area of 3,800 square feet and stretches a distance well more than the length of a football field. The museum's second floor features exhibits detailing the history of the circus from ancient times to the present.

Contact: 941-359-5700 or visit Ringling.org/circus-museum.

Lower East Side Tenement Museum in New York, New York

Searching during the late 1980s for a site to establish a museum honoring American immigrants, historians and social activists Ruth Abram and Anita Jacobson made a startling discovery. They came across a dilapidated tenement house at 97 Orchard Street on New York's Lower East Side its dark, dingy rooms, narrow hallways and communal bathrooms still largely intact.

Dating back to 1863 and inhabited through the early decades of the 20th century by a mix of Irish, German-Jewish, Greek and Italian immigrants, 97 Orchard Street proved an ideal site for a museum aimed at depicting firsthand the lifestyles and adversities of newcomers to America during the nation's peak period of immigration.

So far, conservators and urban archeologists have painstakingly "read" through the layers of the building's history, restoring six apartments in the four-story structure. You can join a tour at the Museum Shop on the corner of Orchard and Delancey Streets.

Contact: 877-975-3786 or visit Tenement.org.

Pioneer Village in Minden, Nebraska

For anyone with a keen interest in American history, a visit to Pioneer Village is a must. This crazy-quilt assemblage of nearly everything you'd find in grandma's attic or grandpa's garage represents one of the nation's largest collections of Americana.

Located just south of Interstate 80 in south-central Nebraska, the Pioneer Village complex is comprised of 28 buildings scattered over 20 acres. A dozen relocated historic buildings including a pony express station, a church, general store, toy store and doctor's office surround a picturesque Village Green.

Several larger buildings serve to warehouse a mind-boggling assortment of more than 50,000 items large and small dating back to the early 1800s, including an immaculate steam-powered carousel and examples of multiple modes of transportation 350 antique cars and trucks, 100 vintage tractors, 17 flying machines, several covered wagons and an 1822 ox cart.

Contact: 308-832-1181 or visit PioneerVillage.org.

American Sign Museum in Camp Washington, Ohio

Signs are all around us as we move about, showing us the way, inviting us in or exhorting us to buy. Signage is so copious and commonplace in our busy, commerce-driven world that most of it passes us by unnoticed.

Tod Swormstedt, owner and curator of the American Sign Museum, is trying to change that by making us more aware of signs and their value to businesses and communities.

Swormstedt shares a lifelong interest in signage and a collection of more than 500 signs from the 1800s to the 1970s with visitors to his 20,000-square-foot museum in the Washington Camp neighborhood of Cincinnati. He contends that signs are a fascinating reflection of the history, technology, commerce, and culture of our country.

So if the hum of neon and recollections of those colorful relics that dotted the highways and main streets of yore make you nostalgic, a visit to the American Sign Museum will send you daydreaming down memory lane.

Contact: 513-541-6366 or visit AmericanSignMuseum.org.

Musee Mecanique in San Francisco, California

Should you ever be strolling on Pier 45 at San Francisco's Fisherman's Wharf and find yourself confronted by a maniacal sounding laugh don't be alarmed. It's more than likely emanating from "Laffing Sal," a vintage mechanical funhouse fat lady residing at Musee Mecanique, home to one of the world's largest privately-owned collections of mechanically-operated musical instruments and antique arcade machines.

The quirky collection here ranges from turn-of-the-century hand-cranked music boxes to an assortment of arcade games that traces their development from mechanical to video. Most of the old machines still work and you can play them for a mere quarter! arm-wrestling with one or challenging another to a mind-reading game. And for the millennial set, there's Pac Man and Skee Ball.

Contact: 415-346-2000 or visit MuseeMecanique.org.