Belly Up Bible Retreat

Well, this is based on the book and story of Jonah.
You go into a place, can be in the church building or in a house, depending on the size of your group.
You get the kids to bring flashlights, sleeping bags, pillows, food and drinks, and most importantly, their Bible.
You turn out the lights, and you spend 24 hours in the dark. You spend this time studying Jonah, playing games related to that book, and doing other things you can in the dark. Allowing the kids to sleep any time they need to and awaking when they feel like it.
Do NOT allow watches or clocks in the building. Choose a room close to a bathroom.
Get someone to agree to get the group when the 24 hours are finished.
This is a good way to get a slight idea of how Jonah might have felt.