Each door has a window, through which you catch glimpses of sunlight and trees. In order, the nearest doors are labelled "North America Plains," "Amazon Basin River Community," "Temperate European Forestland," and "North American Desert." Moving shadows on the windows indicate waving tree branches and flitting birds. You can hear, faintly, the cries of coyotes and strange jungle noises.
As much as you wouldn't mind exploring, you know you should go back.