Couldn't come up with too many franchises to use for Adventureland that have not already been used there (i.e. Aladdin, Indiana Jones). Only came up with three attractions, may add more later.
Pride Rock is such a recognizable structure that it seems like the perfect figurehead for a new Adventureland. Lion King is still a popular, loved franchise. A roller coaster cart would bring guests up and through the inside of Pride Rock on on the outside where Rafiki is holding baby Simba up. The attraction would be the favorite characters from the movie.
Trip to Treasure Island
Disney has a rich history with Robert Louis Stevenson's greatest story. It was their first live action film and served as inspiration for Muppet Treasure Island and Treasure Planet. This attraction is based on Rafts to Tom Sawyer Island. Except it would be a ship bringing people to an abandoned island where they look for Captain Flint's treasure. A fun boat ride and walk through.
Journey Through the Jungle Book
Another dark ride, but as you can guess based on the Jungle Book. I think the best dark rides are the ones with the best characters. Even if the movie itself isn't the best, if the characters are fun it is a fun time (ala Alice in Wonderland). The characters and setting from Disney's Kipling adaptation are recognizable and beloved enough to make the perfect setting for a dark ride.