This is an event sponsored usually by your school or place of business. The idea is that through some sort of outdoor team building exercises, you'll bond as a group with the others involved, and become a better leader/producer in the process.

This is never the case. You are required to go by whatever institution is sponsoring the event, or at least the other options are made to look exponentially worse than the retreat itself (like more work). You go to some place in the woods, that is a summer camp run by hippies during the summer, which is converted into a leadership building institution during the non-summer season in order to pay the rent.

Now, on arriving at this location, the competition to be in awkward positions for photo ops as well as come up with good solutions to stupid problems begins. For instance, a favorite is, get everyone in a ten person group to stand on a one foot wide box. For five minutes, everyone tries to stand on the box, despite them knowing themselves, personally, that due to the wonder of network effects, not everyone will be able to succeed. Someone says: "We can all hold hands in a circle and then fall backwards, in a sort of friendly and teamwork style way, leading to us all standing on the box while being able to consume more area then we otherwise would be able to." The reason nobody does this at first is not because they have not developed leadership skills, or because they cannot work together as a team. The reason is, nobody wants to hold anyone else's hand if they can avoid it. The people gradually realize that it cannot be avoided, and the challenge, or adventure is completed (note use of sarcastic, leadership retreat style rhetoric).

The magic of leadership retreats is that whoever organizes it either doesn't go, or secretly enjoys paining others and themselves, and everyone gets to say that they learned leadership, which always looks good on resumes and doesn't take much explanation. What's more, whoever the real leader is gets to control the people involved by threatening to send them on another leadership retreat.