When did Disneyland theme park start to feature a resort?

Disneyland Park does not have a built-in resort. However, there are several hotels located within the Disneyland Resort, which is the larger area that includes both Disneyland Park and Disney California Adventure Park. The first hotel to open within the Disneyland Resort was the Disneyland Hotel, which opened in 1955, the same year that Disneyland Park opened.