Did you know you can order a quesadilla-burrito hybrid at Chipotle? Or not all footlong Subway subs are 12 inches (30cm)? There's more than meets the eye to your favourite fast food restaurants. From secret menu items to royal owners and burger and fries-scented candles, here are amazing facts that will make your jaw drop.

You might be familiar with Domino’s drivers ringing your doorbell, but in Australia and Houston, Texas, the global pizza chain is testing delivery robots. The golf-cart-size cars are able to navigate their way to customers' homes using GPS and sensory technology.

Domino’s customers who lived in Whangaparaoa, New Zealand, a town 20 miles (32km) north of Auckland, were once able to have pizzas delivered by air. The drones, launched in 2016 as part of a test, delivered within roughly a mile (1.5km) of the store and travelled 18 miles per hour (30kmph). While the drone used is now enjoying retirement at a museum in Auckland, Domino's continues to study this delivery method for the future.

The global sandwich chain has only been known as Subway since 1968. Prior to that, it was called Pete's Super Submarines after one of its founders, Dr Peter Buck. He teamed up with high school graduate Fred DeLuca in 1965 when the average cost of a sub was 49 cents (39p).

At one point, it was easier to get your hands on a Meatball Marinara than a Big Mac or a Frappuccino. Subway had more than 42,000 restaurants in October 2020 making it the largest fast-food chain at the time. However, as of May 2022, Subway's numbers decreased to 36,840 stores worldwide and McDonald's hit 40,031, successfully overtaking it as the largest fast-food chain. 

In fact, a lawsuit was even filed against the chain after a number of sandwiches measured up short in 2013. However, it was concluded natural variability in baking means it's inevitable subs will be slightly different sizes and no customer is actually missing out on food.

Every time Chick-fil-A opens a new store, the first 100 people to buy a meal receive free food for a year. Keen customers are known to wait in the car park overnight, known as the First 100 Campout, so you better arrive early.

Diner chain IHOP is renowned for its pancakes, but did you know it adds the batter to its omelettes too? It's what makes the breakfast classic extra fluffy and sweet.

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This off-menu item at Chipotle is made by preparing a burrito with a cheesy quesadilla instead of a plain tortilla. But beware, due to its popularity you’ll be charged an extra $3.50 (£2.85) for this delicious meal.

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It’s not uncommon to think Pizza Hut is named after its restaurants' roof shape. However, there's no profound reason behind its name. Founders Frank and Dan Carney went with what they could fit on the sign.

Read more about the incredible history of pizza

Back in 2001, Pizza Hut delivered a pizza to Russian astronaut Yuri Usachov while he was at the International Space Station. The lucky pizza reportedly hitched a ride on a Russian rocket to get there. The stunt didn’t come cheap for Pizza Hut though – it is said to have cost the company around $1 million (£812,000).

Above a KFC, across the street from the Great Sphinx and Pyramid of Giza, is this prime-location Pizza Hut. Why battle the crowds and the heat when you can sit back in an air-conditioned dining room with a pepperoni pizza, soda and an unobstructed view of an ancient wonder.

Everyone loves Ben & Jerry’s ice cream because of the huge chunks of sweet treats like marshmallow, brownie and chocolate. Beyond an intense sugar rush, there’s a more thoughtful reason why they’re in there. One of the Ben & Jerry's founders, Ben Cohen, suffers from anosmia (loss of smell) so texture is very important to him.

The innovative duo had even decided a name for the business – UBS, meaning United Bagel Service. Then they found out how expensive bagels were to make and bought an ice cream machine instead. We’re happier for it, otherwise we wouldn’t have Phish Food and Cookie Dough.

The convenient restaurant chain, open 24/7 and 365 days a year, is an official meeting place for people using the Roadie delivery app. App users agree to pick up and drop off other people's packages on a journey they're making anyway and it’s quicker than UPS or FedEx. Eating waffles beats standing in the queue at the post office any day.

It might be called Waffle House after the sweet and golden breakfast dish, but the American chain is actually one of the world’s largest purveyors of T-bone steaks. It sells them at a rate of four per minute.

Find out how to cook restaurant-quality steak at home

If you love Nando's but aren’t a fan of the spice, there’s another flavour option available to UK customers that isn't on the menu: barbecue sauce. It’s called Peri-Tamer and is used on kids' meals. It’s not advertised but is extremely popular, so don’t be afraid to ask.

McDonald’s chicken McNuggets come in four different shapes and they all have names: the boot, the ball, the bone and the bell. See how many you can spot next time you pick up a box.

Back in the late 1980s-1990s, McDonald’s introduced pizza to menus at select stores in the USA. It came with toppings such as cheese, pepperoni, green pepper and onion, but was eventually phased out due to issues such as slow cooking times. Don’t you wish you could order one now?

Take a look at more fast food failures we wish would make a comeback

Crazy, right? But with McDonald's typically receiving 68 million visitors a day and nearly 15% wanting Happy Meals, all of those toys add up. The chain is the largest distributor of toys in the world.

A classic McDonald’s menu choice in the Philippines is Chicken McDo with McSpaghetti. The order consists of one piece of crispy chicken served with spaghetti in a minced beef and tomato sauce, topped with cheese. We wouldn’t say no to it.

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In the days before Ronald McDonald was on the scene, the McDonald's mascot was a miniature animated chef named Speedee. He appeared on restaurants’ signs in the 1950s, before being replaced by the golden arches.

The Bell was Taco Bell's themed pop-up resort that opened in Palm Springs. Open for only one weekend, the hotel sold out immediately. While the investment seemed a bit high for a weekend-only venture, the hype it created accounted for 75% of Taco Bell’s media impressions for the year. This isn't surprising, Taco Bell has garnered a cult following with some people even getting tattoos of the iconic sauce packages.

Although you’re unlikely to spot her eating a Big Mac, The Queen owns a McDonald’s restaurant at the Banbury Gateway Shopping Park, 80 miles (129km) northwest of London. It's part of The Crown Estate, the monarch’s land and property portfolio, which includes Ascot Racecourse and London’s Regent Street.

This is the incredible story of how McDonald’s conquered the world

Food and drink the royal family won't touch

If you want a Whopper in Australia, you're heading to Hungry Jack's, not Burger King. It's the Australian franchise of the brand and has all the same menu items you know and love.

Yes, it is totally possible to order a combination of fries and onion rings at Burger King. The dream menu item, also known as Frings, is available on the secret menu at any branch that sells the sides separately, so you don’t have to decide between them.

The capital of Finland is known for its saunas and one Burger King branch even launched its own in-restaurant spa in 2016 where you could be served regular burgers, drinks and alcoholic beverages while sweating it out in the 15-person sauna. We'll leave you to decide whether that sounds like a pleasant experience or not.

People all over the world can't get enough of KFC, and in Japan it's even a staple on Christmas Day. Thanks to a very successful ad campaign that ran half a century ago, it's a finger-lickin' festive tradition for many Japanese people to this day.

For KFC, finger-lickin' good isn't only about chicken. The fast-food brand has gained a cult following through some incredibly left-field ventures, including chicken-flavoured edible nail polish, chicken and flower bouquets for mother's day and limited-edition KFC-branded Crocs. Even more surprising is most of these partnerships have sold out faster than the time it takes to eat a portion of Popcorn Chicken.

Did you know you could 'chick-in' to a KFC hotel? KFC opened the doors to House of Harland, a fried chicken-themed apartment, for 11 days in August 2021. The pop-up in London's Shoreditch neighbourhood had a plush cinema room showing chick flicks (get it?), an arcade machine and drumstick-themed décor, from the posters on the wall to the bedding. The best part was the 'press for chicken' button, so a boneless bucket was never far away.

Have you ever dreamt of walking into your room and smelling the sweet scent of that first bite of a Shake Shack burger in the park? No? Well, whether you have or not, it's a possibility thanks to Shake Shack's partnership with candle brand Apotheke. The candle comes in two different scents: "Burger In The Park" and "Shake & Fries" and the experience will only set you back $42 (£34).

Are these the most incredible fast food locations around the world?