A mortarless parapet wall constructed of a plurality of segmental wall blocks positioned to form multiple, stacked courses stacked in an array of superimposed rows: each segmental wall block comprising: two or more face units each comprising a front face, a rear face opposite the front face, an upper surface, a lower surface opposite the upper surface, and one or more channels formed in the rear face, the channels extending from the upper surface to the lower surface along a face unit height, the rear faces of the two or more face units oriented to face each other; one or more anchoring units each comprising a central portion extending from a first end to a second end, each anchoring unit having a first side surface and a second side surface opposite the first side surface, the first end flaring laterally outward of the central portion to form a first connector, the second end flaring laterally outward of the central portion to form a second connector, the first and second connectors being sized to slide into and be interlocked with the channels of the two or more face units, one or more of the anchoring units positioned such that at least one of the first and second connectors is interlocked with the channels of at least one of the two of the face units; a granular fill or soil filling gaps between the rear faces of the two or more face units oriented to face each other, the granular fill stabilizing and reinforcing the parapet wall; and wherein, for at least one of the plurality of segmental wall blocks of the parapet wall, the one or more of the anchoring units are positioned such that the first and second connectors are interlocked with the channels of both of the two of the face units; and wherein, for at least another one of the plurality of segmental wall blocks of the parapet wall, the one or more of the anchoring units positioned such that the first connector is interlocked with the channel of one of the two of the face units, and the second connector confronts the soil or the granular fill between the two of the face units, the flaring of the second connector providing an anchor in the soil or granular fill to resist movement and provide stability. each segmental wall block comprising: two or more face units each comprising a front face, a rear face opposite the front face, an upper surface, a lower surface opposite the upper surface, and one or more channels formed in the rear face, the channels extending from the upper surface to the lower surface along a face unit height, the rear faces of the two or more face units oriented to face each other; one or more anchoring units each comprising a central portion extending from a first end to a second end, each anchoring unit having a first side surface and a second side surface opposite the first side surface, the first end flaring laterally outward of the central portion to form a first connector, the second end flaring laterally outward of the central portion to form a second connector, the first and second connectors being sized to slide into and be interlocked with the channels of the two or more face units, one or more of the anchoring units positioned such that at least one of the first and second connectors is interlocked with the channels of at least one of the two of the face units; a granular fill or soil filling gaps between the rear faces of the two or more face units oriented to face each other, the granular fill stabilizing and reinforcing the parapet wall; and two or more face units each comprising a front face, a rear face opposite the front face, an upper surface, a lower surface opposite the upper surface, and one or more channels formed in the rear face, the channels extending from the upper surface to the lower surface along a face unit height, the rear faces of the two or more face units oriented to face each other; one or more anchoring units each comprising a central portion extending from a first end to a second end, each anchoring unit having a first side surface and a second side surface opposite the first side surface, the first end flaring laterally outward of the central portion to form a first connector, the second end flaring laterally outward of the central portion to form a second connector, the first and second connectors being sized to slide into and be interlocked with the channels of the two or more face units, one or more of the anchoring units positioned such that at least one of the first and second connectors is interlocked with the channels of at least one of the two of the face units; a granular fill or soil filling gaps between the rear faces of the two or more face units oriented to face each other, the granular fill stabilizing and reinforcing the parapet wall; and wherein, for at least one of the plurality of segmental wall blocks of the parapet wall, the one or more of the anchoring units are positioned such that the first and second connectors are interlocked with the channels of both of the two of the face units; and wherein, for at least another one of the plurality of segmental wall blocks of the parapet wall, the one or more of the anchoring units positioned such that the first connector is interlocked with the channel of one of the two of the face units, and the second connector confronts the soil or the granular fill between the two of the face units, the flaring of the second connector providing an anchor in the soil or granular fill to resist movement and provide stability.