Tomorrowland is where you enter the world of the future, as it was envisioned by Walt Disney. The land originally had inspirations from Jules Verne's 20,000 Leagues Under The Sea, but over time has primarily focused on more of a space age future.
Tomorrowland in 1996: Image By Ellen Levy Finch Elf assumed (based on copyright claims), CC BY-SA 3.0, Link
Opening day Tomorrowland was mainly filled with different halls showing movies, exhibits and an attraction that you can still ride to the day, Autopia. Over the course of the first year Tomorrowland gained several new rides, most closing in the next few years leaving room for newer and faster rides.
Today Tomorrowland is host to some of the most popular rides in the park, such as Space Mountain, Star Tours and Buzz Lightyear Astro Blasters. While this land started out with inspirations from the futuristic mind of Jules Verne it has gone on to host rides inspired by Disney brand commodities Star Wars, Toy Story and Finding Nemo.
Tomorrowland from Space Mountain: Image By CC BY-SA 3.0, Link