In the Middle Ages, people often slept in box beds. These fully enclosed beds were enclosed inside of a wooden box with a door that could shut to fully close off the sleeper from the outside world.

New airplane beds . 1 of 12. Air France's La Première First Class. ... with Singapore Airlines' all-new A380 Suites and Emirates' fully-enclosed 777 seats. ...

Nowadays, though, traces of the bed cupboard remain—and are quietly transforming modern homes. So while we certainly don't suggest that you sleep in a claustrophobic closet, there seems to be an ...