It is easliy forgotten, but the Village is situated on an estuary. The mouth of the estuary leading into the sea, and the river leading into the hills and mountains beyond. So perhaps that is a possible way out of the Village, an escape route to freedom. All one would need is a dug-out canoe, Number 6 could easily carve one out of the trunk of a tree. But then perhaps he's had enough of felling trees, and contructing sailing craft!