The equator is really just a fancy name for the line of zero degrees latitude. Of course, Giovanni Domenico Cassini created the latitude/longitude system in 1681 (give or take a century), so until that time the equator wasn't there and the Earth had a large gap in the center, causing hikers to meet an early demise.
Climate and geography
The equator is one of the warmest countries on the planet. It is excessively humid in its many rivers and coca-cola vending machines. Temperatures can get to really, really hot, Fahrenheit.
The equator is home to many natural features, such as rainforests. Rainforests are where you cut trees down because they would do something horrendous if you didn't. No one knows quite sure what might happen but no one wants to take the chance, either.
There are also many other geographical features on the equator as well. One of the largest and most noticeable are the mountains. These triangle-shaped things are among the most beautiful sites on Earth, or so the tourist manual says. Popular mountains to visit are usually located near patches of rainforest that has been cleared of its evil trees.
Today, the equator is the main boundary between the northern and southern hemispheres. Without it, the northern hemisphere's inhabitants would fall to Antarctica. One famous example of this is when a blind man was hiking throughout the world and didn't look where he was going. Naturally he tripped and fell into the void of the Earth. The legend goes that if you listen hard enough, you can still hear his faint screaming, right before you realize you were laying in a pile of dung from an exotic and nearly extinct animal.
In addition, previously the world was largely separated (before the invention of the internet). The equator unified places such as South America and Africa. It brought trade and ideas to each: Africa enjoyed enchiladas while South America... well, South America didn't get much. But the equator connected many more countries as well. It made them all miserably hot and gave them common ground to complain about something they could all relate to.
Unfortunately, not every role is positive. The equator has an extensive amount of vegetation; it's almost disgusting how much vegetation there is. Time after time, travelers fatigued from the heat would stop to take a rest, only to find that 1) they didn't know where the hell they were, for there were vegetation and crap all around them, and 2) there was a large, vicious, rainforest-ish animal ready to pounce. This greatly lowered the popularity of visiting the equator for ten years until a desperate advertising campaign promised free beer to all who wanted it. Of course, this was just Nigeria cutting in, but some people still believed it anyway. Their bodies were later found being digested in a rare species of plant similar to the Venus Fly Trap.
The equator: a dense, hot, savage place filled the brim with excitement. It is easy to see why adventurous people would lead parties into the place, for personal gain and eternal glory.
One such man was Marco Polo. Rather than heading into the jungle, his party took a wrong turn and instead, discovered the equator running along an ocean. This intrigued Polo who lead everyone onto a ship to explore the ocean. Perhaps his most famous moment was when he fell overboard after sunbathing in the nude, and frantically shouted out "Marco! Marco!" It is unknown why he continued to shout out his first name rather than something more practical, such as "get me the hell out of here I'm drowning aaaghh!" A man on deck heard his vicious screaming and alerted the crew by shouting "Polo! Pooooloo!" Again, it is unknown why he didn't just say "holy crap Marco's in trouble!" or something like that. This has turned into a popular children's game. The goal of the game is to see how fast your friend drowns.
In 1743, a boat carrying a crew of 150 Canadian and Alaskan sailors landed in the Amazon River. For eight months they traveled along the rive, eating nothing but canned goods. They took notes, sketches, and specimens of the exotic birds and frogs that crawled into the ship and slit the throats of the captain and first mate. They returned to the north and televised a speech that gave the world great knowledge and laughs of their fallen leaders.
Perhaps the most famous expedition to the equator was to Africa. Traveling on foot, a group known as the Honklebees of Sweden explored the western regions of Africa and befriended many natives who resided there. The journey that the Honklebees made was not unlike many others, except for the fact that the group consisted entirely of blind people. Their sketches were considered to be incredibly accurate, with precise detail for the colorings of antelope and polar bears. The leader of the group was quoted to say, "So what if I'm blind? It doesn't change what I can't do. If I push myself, I know I can do anything." Later that night, the leader went outside to get some fresh air and tripped on a twig, breaking his neck. So much for blind people on expeditions.