The basic definition of an adventure entails a character or characters going from one place to another for a certain reason. Most of the time this entails traveling through a jungle or across a mountain range or over a long ocean voyage. Include a large number of exotic settings when crafting your adventure story; or set your story in an area that has very extreme areas, or in worlds in which your characters can have an adventure. This will translate well to both the imagination and the screen. The settings should be both beautiful and extreme or dangerous throughout the story, adding a sense of fear or excitement for readers.
Give your characters a reason for going on an adventure, as this will be the engine which drives your adventure story. The better the reason, the more exciting the adventure in most cases. In "Jurassic Park," characters are going to an island to see dinosaurs and then trying to get off the island to get away from the dinosaurs. In "Indiana Jones and the Last Crusade," the heroes are searching for the Holy Grail. Adventure happens along the way, but the basic plot line and reason for the quest drives the story.
As an adventure story will carry characters through exotic worlds, you should also create an array of unique characters. The story's lead character (or characters) should have a unique personality, which can aptly adjust to different regions of the world. Supporting characters should also be interesting in their personalities and motivations, all with a certain amount of depth and character affectations based upon their role in the story. Characters only add to the adventure, adding an entertaining level of humor, darkness or beauty.