An arrangement for attaching a falling post on a base structure, the post being rotatable movable between a standing and a recumbent position, the arrangement comprising - a stand, comprising attachment element for attaching the falling post to said base structure, - the post attached pivotally to the stand by a pin, the post having an ability to rotate from the standing position to the recumbent position in respect of the stand, - the stand comprising at least one groove arranged laterally in respect of the post, and - the post comprising at least one projection extending in a lateral direction from the post, characterized in - said at least one groove being arranged in respect of said at least one projection such that when the stand is in the standing position, the at least one projection lies in the at least one groove, and thereby locks the post in said standing position, - the at least one projection being attached to the post such that it has an ability to move in respect of the stand in a longitudinal direction of the post - an exterior of the stand comprises a guidance surface ending to the at least one groove, and arranged to lift the at least one projection and guide said projection to move in the at least one groove, - the arrangement further comprising a lever attached rotatable in the stand, - the lever including a first end, length of which is arranged to extend past the guidance surface when the post is in the recumbent position such that - the at least one projection arranged to move on the guidance surface is adapted to push the first end of the lever and rotate the lever in first direction therewith, and - the at least one projection arranged to push down the first end simultaneously with moving into the at least one groove, such that the post being in the standing position the first end of the lever is situated under the at least one projection lying in the at least one groove, and wherein - the lever being activated to rotate in a second direction opposite to the first direction, the first end of the lever is adapted to lift the at least one projection away from the at least one groove, thus allowing the post being moved towards the recumbent position. - a stand, comprising attachment element for attaching the falling post to said base structure, - the post attached pivotally to the stand by a pin, the post having an ability to rotate from the standing position to the recumbent position in respect of the stand, - the stand comprising at least one groove arranged laterally in respect of the post, and - the post comprising at least one projection extending in a lateral direction from the post, - said at least one groove being arranged in respect of said at least one projection such that when the stand is in the standing position, the at least one projection lies in the at least one groove, and thereby locks the post in said standing position, - the at least one projection being attached to the post such that it has an ability to move in respect of the stand in a longitudinal direction of the post - an exterior of the stand comprises a guidance surface ending to the at least one groove, and arranged to lift the at least one projection and guide said projection to move in the at least one groove, - the arrangement further comprising a lever attached rotatable in the stand, - the lever including a first end, length of which is arranged to extend past the guidance surface when the post is in the recumbent position such that - the at least one projection arranged to move on the guidance surface is adapted to push the first end of the lever and rotate the lever in first direction therewith, and - the at least one projection arranged to push down the first end simultaneously with moving into the at least one groove, such that the post being in the standing position the first end of the lever is situated under the at least one projection lying in the at least one groove, and wherein - the lever being activated to rotate in a second direction opposite to the first direction, the first end of the lever is adapted to lift the at least one projection away from the at least one groove, thus allowing the post being moved towards the recumbent position.