An apparatus for an a method of closing a fixed gap in an activity surface such as a turfed race-track is described. The apparatus comprises a movable turf tray having an upper surface with the same characteristics as the activity surface and means for guiding the tray into the gap so as to wedge the tray releasably in the gap and thereby to provide a substantially continuous activity surface. The apparatus can be used to provide a reconfigurable racetrack crossing with the permanent road gap in the racetrack being closeable by means of the movable turf tray. Overlapping edges of the turf tray provide a weight wedging action which provides reliable pressure joins. This also has application for creating reconfigurable turfed activity surfaces such as are used in sports stadia and the like.