National Pizza Day is on Feb. 9 each year. 

Most people have likely heard of the classic thin New York slice, or the saucy and rich Chicago deep dish (and the beef between their respective fans). 

But what about Omaha-style pizza, Sicilian style or a grandma slice?

There’s a lot more to pizza than the big cities would have you believe. 

SLIGHT MAJORITY OF AMERICANS WOULD RATHER EAT PIZZA FOR BREAKFAST, SURVEY FINDS

Below are eight regional pizzas you may have never heard of – unless, of course, you live in the area.

Perhaps the most well-known of the unknown, Detroit-style pizza is baked in a deep, square pan, not flat on a pizza pan. 

The result is a rectangular, thick pizza with a tall, chewy crust. 

The chewiness of the crust is also what is said to differentiate this style from other slices.

A Detroit style pizza is typically topped with Wisconsin brick cheese and is spread all the way to the crust of the pizza, making for a crispy, cheesy crust.

Sure, St. Louis catches some flak for its unusual version of things (we’re looking at you, bagels). But the Midwestern state is undeterred in forging its own path – such as with its pizza, which is distinct because of its cracker-like crust typically made without yeast, and its rectangle slices.

This pizza is very thin and crispy. 

VIRAL PIZZA HACK HELPS YOUR GRAB SLICE WITHOUT TOUCHING THE REST OF THE PIE

Similar to the Detroit pizza, this style is also covered with cheese on the entire pizza, including the crust. The pizza is topped with Provel cheese, a combination of cheddar, Swiss and provolone. 

Sicilian style pizza originated in Italy and was known as "sfincione," which translates to "thick sponge," before it made its way to the United States. It's most closely compared to a Grandma slice.

What makes a Sicilian style pizza is its thick, spongy consistency, square shape and its thick crust. Traditional Sicilian pizza is served cold with tomato sauce, Parmesan cheese and no toppings.

"It's an appetizer pizza," said Johnny Ferrara, owner of Ferrara's Imported Foods in Cleveland. "You would eat it with antipasto like dried sausage, olives, peppers, prosciutto, salami and cheese."

Sicilian pizza is made with a sweeter sauce and it's beloved by Italian-Americans.

"We're selling more now because more grandmas are dying and nobody knows how to make their grandma's pizza," Ferrara said. "But it's how we've been doing it for 65 years – no toppings. Nothing on it."

Not to be confused with the square Sicilian slice, which features a thicker crust and usually the cheese on top, a true Long Island Grandma pie is a square pizza that is layered with cheese first, followed by sauce on top.

CLICK HERE TO SIGN UP FOR OUR LIFESTYLE NEWSLETTER

It is then – like the Detroit-style pizza – cooked in a rectangle pan until the crust is crispy. For an even more authentic version, make sure it comes from an actual Italian grandmother.

Though the name might not sound all that appetizing – unless you’re a cold pizza lover – Cold Cheese pizza is probably not what you’re thinking.

The pizza style, which reportedly originated in Oneonta, New York, is not an actual fully cold slice of pizza. 

Instead, it’s a fresh, hot slice of pizza that is then topped with cold, shredded mozzarella cheese. The cult-favorite has since expanded to Pennsylvania and New Jersey.

Iowa and Illinois are coming in hot with what might be the most-unique pizza of the regional styles.

Like many of those on this list, the difference comes down to the crust. Quad-City style uses a pizza crust made with malt. The thin crust is then topped with a spicy sauce, usually made with red chili flakes, before the toppings are piled on, with the cheese on top.

Another unique feature of this pizza is how it is cut. 

The Quad City style pizza is cut in rectangular strips rather than the classic triangle or common square cut. 

Continuing on in the Midwest is the Ohio Valley-style pizza, which is almost a combination of many other styles featured on this list.

It starts as a square pie with thick crust that is then topped with sauce and cooked. Halfway through the bake, the pizza is removed from the oven, topped with more sauce and a thin layer of cheese and toppings, and then thrown back in. 

Once finished, the pizza is removed and topped with cold cheese. It is then served hot-and-cold.

This love-it-or-hate-it style starts with a yeast-free crust that has been described by the Omaha World-Herald as more of a biscuit than an authentic pizza dough. The flaky base – which gets grilled during the cooking process – is then topped with red sauce, mozzarella or Romano cheese (or a little of each) and a heaping helping of ground beef.

According to La Casa, the pizzeria credited with inventing the style, a true Omaha slice reportedly includes mushrooms and onions mixed with the beef.