In 1889, Charles McKim designed the Johnston Gate, a formal entranceway to the campus and the first of his many commissions at Harvard. The gate also was the first full-blown manifestation of the Georgian Revival architecture that would be adopted by Harvard architects through the early decades of the twentieth century. Constructed with coarse handmade brick, evoking the college's oldest buildings, Johnston Gate introduced a material, Harvard brick, which imitated handmade wood-burned brick of the colonial period, that would become a unifying feature of the campus. Other gates followed, linked by the Memorial Fence, begun in 1899, defining and separating Harvard Yard from the bustle of Cambridge. The wooden guardhouse is a postmodern design that contrasts with its brick Georgian and Georgian Revival neighbors. Rather, it subtly alludes to the Victorian buildings on the campus and the nineteenth-century residences nearby.