From the Field Trip website:

Old Pasadena, California

Take a Field Trip with us as we explore the city that gave us the Mars Rover Landing, Scientology, Jackie Robinson, the Occult of Jack Parsons, and the Tournament of Roses - Pasadena, California.

Just north of Los Angeles, the picturesque Southern California city of Pasadena is nestled at the base of the San Gabriel mountains. For decades, train tracks criss-crossed the city allowing layman and celebrity alike to escape the hustle and bustle of Los Angeles for a day of shopping, hiking, and entertainment.

Beyond this beauty, though, there's always been a darker, magical, more rebellious side of Pasadena: a place where religion, magic, and rocket science collided; a haven for free thinkers, outcasts, and eccentrics; a stomping ground for the likes of Albert Einstein, Jack Parsons, Julia Child, and Tennessee Williams, and a home for millionaires like William Wrigley Jr. and Adolphus Busch. Pasadena's landscapes have also stood in for all parts of the world in legendary Hollywood movies and television shows such as Gone With the Wind, Back to the Future, Mad Men, Parks and Recreation, and The Sting.

Field Trip Day is an afternoon of local discovery, challenges, one-day-only opportunities, and hidden surprises. Armed with the Field Trip app and your wits, an afternoon's adventure will reveal Pasadena’s secrets - from rocket launches to peanut butter soda, from the man who broke baseball's color barrier to the man who revolutionized chewing gum, from auditioning for the role of Stanley in "Streetcar Named Desire" to learning the truth about a religious cult... explore Pasadena like never before.

Brought to you by Google's Niantic Labs! The same mysterious group that runs Ingress. You can register for the event and get your FREE TICKETS at Google Field Trip's page here.