The next section, of course, is dedicated to those authors out there that are great at world building. Perhaps not just great, but legendary. These are the authors that I draw inspiration from. Without further ado, here's my list of great world builders.
J.R.R. Tolkien. There are many fantasy writers and most of them, at some early point in their lives, read about the adventures of some Hobbits in Middle Earth. Tolkien is, undeniably, a master story teller and a master world builder. His notes detail a rich fantasy history from it's very first days to the current years of his stories. The geological features of his imaginary continent are based in real geology, right down to the mountain ranges that surround Mordor and Mount Doom. His characters don't just have back story, they have history, back unto generations of family, connections to heroes and villains, saints and cowards. As a result, Middle Earth is one of the most detailed and painstakingly created fantasy worlds.
All of Tolkien's most popular stories are written with a teachable character as the MC, Bilbo in the Hobbit and Frodo in the Lord of the Rings. Some of his other works, like the 'Silmarillion', are written more like a history book without any real main character.
Terry Pratchett. This is the man who churned out quality novels for years in his popular Discworld series, and evolved his fictional world bit by bit with each novel. His most famous of cities, Ankh-Morpork, was a satirical conglomeration of the sins of multiple real-world cities filled with colorful and interesting characters. Pratchett made us believe that a world could exist being spun by four great elephants on the back of a giant space turtle and, you have to admit, that's real magic. Pratchett has admitted in interviews that when he first started writing stories in Ankh-Morpork, he had only the faintest idea of the layout. By the end, he had scale models and detailed drawings of every street and all the important buildings. World building can evolve as you go, and you don't need remarkably detailed worlds in order to tell a good story.
Brandon Sanderson. Sanderson has written an abundance of fantasy and was the one entrusted with closing off the Wheel of Time series after Robert Jordan passed. While Jordan was a giant as well, and the Wheel of Time series has a scope to rival pretty much any other series ever written (Lord of the Rings included) what I really wanted to do was bring attention to Sanderson's knack for unique magic systems. Check out Warbreaker that he posted on wattpad here: https://www.wattpad.com/story/6828459-warbreaker if you don't believe me. Anyone who can devise a magic system powered by color and the power of a person's breath (soul) deserves to be recognized as a great world builder.
Margaret Weis and Tracy Hickman. These two have been cooking up worlds for fantasy and science fiction fans alike for decades and perhaps could be considered the two authors that laid the foundation for most of the stories written in the Dragonlance series. Aside from their work with all things dragons, the Death Gate Cycle is seven books of pure world building genius. A common theme in their storytelling, many of their stories at first appear to be fantasy when they later reveal themselves to have a firm foundation in science. Well, firm-ish. They've always written in a high fantasy style as opposed to a hard sci-fi flavor. The worlds that they've designed have been the seeds for dozens of authors to pick up their own pens and add colors and dimensions. For this reason, these two are worth looking up to as examples of great world building.
Of course there are more. There are millions more. Card, Naovik, Gaiman, Endings, Herbert ... the list goes on and on. For fun add some of your favorite world builders in the comments. Maybe we can share some stories that we wouldn't have known about otherwise.