A small door, they range from two to three feet square, usually a square shape, although rectangles and circles do exist. They are commonly made of wood, either a high quality wood or other wood of special significance, sometimes can be made of metal or stone, but that does detract from it’s portability. It has a handle but no hinges.
To use this item, just place it against a flat surface and pull the handle. The edge facing the surface is rooted in place and the area the door covered is now a portal into a comfortably sized room about twenty cubic feet. Anything placed inside the room is imobilized while the door is in transit, so nice furiture and expensive vases have no greater risk of damage than those that normally encounter an adventuring party. When newly enchanted, rooms are unfurnished and the fireplaces are not standard as the spells required to make an extra-dimensional flue are complicated.
To ready the item for transport, simply grasp two opposing edges and lift. Some doors are equipped with command words to attach and release to help prevent the occupants from being carried off while resting. All door may be mounted to any horizontal or vertical flat surface, even upside down as many door have rungs or other hand holds along the entrance. Once inside, the sense of up reverts to the doors floor, oppisite the entrance. Doors with rooms that are entered into from the side are very rare as the doors as commonly used on streets and trails where a sewer lid style entrance is more accomodating. After all, how many vertical surfaces can one find in the forest?
This door does not help heal wounds or resist aging, it merely provides a dry spot to get out of the weather. The room does not provide provisions nor does it magically preserve anything left inside, although particulaly old doors may have had things left inside by previous owners that may have become a bit ripe or worse, animate. The room is an extra-dimensional space and react accordingly to contact with other extra-dimensional spaces. Any amount of material may be placed inside the room with little impact to its weight, which is that of a door of the size in question.