I went to Disneyland YEARS ago. But, it was before I bore children. Son is almost 21, and is taking a trip to Anaheim for other reasons with 3 other friends, all 20-21. They have one day they can dedicate to Disney. Obviously, because they are young men, they have no interest in the "kids stuff". So, the question is: Can they do both Disneyland and California adventure in one long, no break day if they only are interested in the things that would interest 21 year old guys? And if not, which would be better for them to do? When I was there, California Adventure did not exist. Also, is there a one day ticket that would cover both parks? Thanks for any help you can give!