When Disneyland first opened, it looked a great deal different than it does today. Walt Disney envisioned the park as an ongoing development, with new rides arising to augment and replace the old. The original attractions reflected different sensibilities, though all remain true to Disney's innovative spirit.
Disneyland first opened in July 1955. The "original" rides were either in place when the park opened or under construction and opened within a few months.
The original rides relied more on live action performers in 1955 than they do today. For instance, an Indian Village originally in Frontierland featured actors portraying Indians engaging in Native American activities.
The attractions of some areas, have aged better than others. Out of 11 original rides and attractions in Tomorrowland, only one--the Autopia--is still running, whereas eight of the nine original Fantasyland attractions are still in operation today.
The comparatively limited space at Disneyland meant that the original rides needed to compete with newer concepts. When one became dated and forgotten--such as the Hall of Aluminium Fame in Tomorrowland--it closed in favor of a new one.
Fourteen of Disneyland's original rides and attractions are still working today: Main Street Cinema, Disneyland Railroad, Main Street Horse-Drawn Street Cars, Casey Jr. Circus Train, Storybook Land Canal Boats, Dumbo Ride, Snow White's Scary Adventures, Peter Pan, Mad Tea Party, Mr. Toad's Wild Ride, King Arthur Carrousel, Mark Twain Riverboat, Golden Horseshoe and the Jungle Cruise.
Adventureland opened with just a single ride in place--the Jungle Cruise--which remains there today and has become one of the park's most beloved attractions.