All aboard at Fisherman's Wharf, San Francisco, CA. If you have the time, take a cable car ride from Fisherman's Wharf to Union Square and walk back to the Wharf through Chinatown. The fare is $6 and the ride is around 20 minutes. Just make sure you get a view. Riding on the outside holding on is encouraged for adults, and, well quite a bit of fun. The walk back to the Wharf is about 1 hour depending on the amount of time you spend in Chinatown. Don't forget to get some candied ginger.
cable car ride, chinatown, fisherman's wharf, union square