An orientation and/or position estimation system comprising: a movable image capturing unit (4, 6) configured to be held by a user and having an image capturing section configured to capture a surrounding area; a stereoscopic image providing unit (3, 5) including at least one display portion configured to display a stereoscopic image composed of a left-eye image and a right-eye image having parallax therebetween, a contact portion configured to come into contact with a part of a face of the user who is viewing the stereoscopic image, and a detection subject portion (202, 211) configured to be captured by the image capturing section of the movable image capturing unit that is being held by the user; a connection portion having one end connected, by means of a holding operating portion, to a part of the movable image capturing unit (4, 6) and the other end connected to a part of the stereoscopic image providing unit (3, 5), the holding operating portion having a mounting portion to which the movable image capturing unit (4, 6) can be mounted, wherein after mounting the image capturing unit (4, 6) is fixed such that the image capturing section thereof faces the user side, a detection section (81, S2) configured to detect a detection subject portion image indicating the detection subject portion and included in an image captured by the image capturing section; a specifying section (81, S2) configured to specify a position and/or a shape, in the captured image, of the detection subject portion image detected by the detection section; an estimation section (81, S4) configured to estimate an orientation and/or a position of the movable image capturing unit on the basis of the position and/or the shape, specified by the specifying section, of the detection subject portion image in the captured image; and an image generation section (81, S6, S8, S10) configured to generate the stereoscopic image to be displayed on the at least one display portion, on the basis of a result of the estimation by the estimation section. a movable image capturing unit (4, 6) configured to be held by a user and having an image capturing section configured to capture a surrounding area; a stereoscopic image providing unit (3, 5) including at least one display portion configured to display a stereoscopic image composed of a left-eye image and a right-eye image having parallax therebetween, a contact portion configured to come into contact with a part of a face of the user who is viewing the stereoscopic image, and a detection subject portion (202, 211) configured to be captured by the image capturing section of the movable image capturing unit that is being held by the user; a connection portion having one end connected, by means of a holding operating portion, to a part of the movable image capturing unit (4, 6) and the other end connected to a part of the stereoscopic image providing unit (3, 5), the holding operating portion having a mounting portion to which the movable image capturing unit (4, 6) can be mounted, wherein after mounting the image capturing unit (4, 6) is fixed such that the image capturing section thereof faces the user side, a detection section (81, S2) configured to detect a detection subject portion image indicating the detection subject portion and included in an image captured by the image capturing section; a specifying section (81, S2) configured to specify a position and/or a shape, in the captured image, of the detection subject portion image detected by the detection section; an estimation section (81, S4) configured to estimate an orientation and/or a position of the movable image capturing unit on the basis of the position and/or the shape, specified by the specifying section, of the detection subject portion image in the captured image; and an image generation section (81, S6, S8, S10) configured to generate the stereoscopic image to be displayed on the at least one display portion, on the basis of a result of the estimation by the estimation section.