In 2003, the Maryland Geological Survey reported that based on a shoreline interpreted from air photos flown between 1988 and 1995, Maryland's tidal shoreline, bordering the Chesapeake Bay, its tributaries, the coastal bays, and the Atlantic coast, is 7,719 miles long. This figure far surpasses the previously reported and frequently cited length of 3,190 miles (The Coastline of the U.S.) or 4,360 miles (U.S. Army Corps of Engineers). Part of the increase is due to the inclusion of minor bay tributaries, the upstream sections of larger tributaries, and streams draining the interior of some marshes.

The Astrodon was a sauropod that weighed up to 20 tons and lived in Maryland during the Early Cretaceous period, from 95 to 130 million years ago. Its name means "star tooth" and derives from the fossils found in 1858 by Philip Tyson. His discovery of two teeth in the Arundel Clay near Muirkirk in Prince George's County was one of the earliest dinosaur finds in America and the first in Maryland. Tyson gave the teeth to a local dentist, Christopher Johnston, who sliced a tooth into cross sections, discovering a star pattern.

The first Ouija board was invented in Baltimore by Elijah Bond. When he asked the board what it wanted to be called, it allegedly replied: "O-U-I-J-A".

The "Mobtown" nickname was bestowed on Baltimore for its history of riots. Some sources trace the nickname to 1812 when a mob of several hundred people leveled the offices of Alexander Contee Hanson's Federalist leaning newspaper, Federal Republican, over its anti-war stance.

The highest point in Maryland is Hoye Crest at 3,360 feet above sea level on Backbone Mountain. The absolute lowest point in Maryland is a natural depression in the bottom of Chesapeake Bay, often called Bloody Point Hole.

It's unclear exactly how Assateague Island's wild horses came to the island, but the legend that they escaped from a shipwrecked Spanish Galleon is most likely untrue. The more plausible explanation is that they are the descendants of horses that were brought to barrier islands like Assateague in the late 17th century by mainland owners to avoid fencing laws and taxation of livestock.

Maryland was home to the country's first umbrella factory (1828), first railroad station (1830), and first dental school (1840).

Black-eyed Susans (Rudbeckia hirta) are common in Maryland fields and roadsides, and the black and gold colors match the state bird, state insect, and even the state cat.

Maryland is known for its excellent cuisine, especially for all things crab. In Maryland, crabs are seasoned and then steamed, not boiled, to ensure maximum flavor and optimum texture.

Smith Island Cake has eight to fifteen layers and chocolate frosting between each layer. The recipe originated in the 1800s when Smith Islanders would send these cakes with the watermen on the autumn oyster harvest. The bakers began using fudge instead of buttercream frostings, as cakes frosted with fudge lasted much longer than cakes with other types of frosting.