kinda, sorta. The main entrance to BOTH parks is just at the end of Downtown Disney, one each side of the esplanade. However there is an entrance into Californian Adventures in the Grand California Hotel. You can only use this entrance if you enter the Grand California Hotel through Downtown Disney. There may be time restrictions for non Grand California Hotel guests. I know that they dont allow non Grand California Hotel guests to enter by the main street entrance of the Grand California Hotel.