Ditch Day, one of Caltech’s oldest traditions, took place on May 26.

During this annual spring rite—the timing of which is kept secret until the last minute—seniors ditch their classes and vanish from campus. Before they go, however, they leave behind complex, carefully planned out puzzles and challenges—known as “stacks”—designed to occupy the underclassmen and prevent them from wreaking havoc on the seniors’ unoccupied rooms.

A few of the day’s images can be seen here. Also check out Caltech’s Facebook, Twitter, Snapchat (search for “CaltechEdu”), and Instagram pages and join the conversation by sharing your favorite Ditch Day memories and using #CaltechDitchDay in your tweets and postings.

Time to Crack Some Stacks—It’s Ditch Day! Ditch Day, one of Caltech’s oldest traditions, took place on May 26. Ditch Day, one of Caltech’s oldest traditions, took place on May 26. During this annual spring rite—the timing of which is kept secret until the last minute—seniors ditch their classes and vanish from campus. Before they go, however, they leave behind complex, carefully planned out puzzles and challenges—known as “stacks”—designed to occupy the underclassmen and prevent them from wreaking havoc on the seniors’ unoccupied rooms. A few of the day’s images can be seen here. Also check out Caltech’s Facebook, Twitter, Snapchat (search for “CaltechEdu”), and Instagram pages and join the conversation by sharing your favorite Ditch Day memories and using #CaltechDitchDay in your tweets and postings.