Llandaff was placed on the National Register of Historic Places by the United States Department of the Interior in 2002.
From the Maryland Historical Trust web site:
“Llandaff House is a 2 1/2-story irregular plan frame house built in 1877-78 at the end of a long tree-lined lane. The house faces south with the principal roof oriented on an east-west axis. The steeply pitched hip roof features three interior and exterior paneled chimneys, multiple gable-roofed extensions, and large 6/6 sash dormers. Originally the top of the chimney stacks flared with a wide corbelled cap, however the tops of the chimneys retain only a few courses of corbelling. The walls are covered in a combination of plain wood and fishscale and other styles of imbricated shingles. The asymmetrical front facade has a central entrance incorporated in a projecting two-story, two-bay pavilion distinguished by an open porch on the first floor. Now supported by clusters of Tuscan columns on piers, this porch originally featured turned posts and a spindled and stickwork frieze and a stickwork balustrade. A c. 1880s photograph shows the entrance bay of the porch surmounted by a pedimented pavilion with a paneled frieze, but this was removed by the time of a c. 1900 photograph, which shows the second floor of the pavilion extended out to the edge of the porch and a lunette window introduced in the gable. In the c. 1900 photo, the floor and balustrade of the porch extended around the west side of the house. Most of the windows are 6/6 sash, and some have multiple panes, crown moldings, dentiled cornices, brackets, or scrollwork beneath the sills. The interior follows an irregular center hall plan with a variety of rooms extending from each side. The center hall is dominated by a turned post staircase distinguished by a closed stringer, square fluted balusters, and a molded handrail. Each of the principal door openings is framed by complex Victorian surround molding, which frames nine-panel doors on intricately cast door hinges. West of the stair hall is a large L-shaped parlor, reported to have been two rooms initially, but combined c. 1900. The Victorian mantel in this room has a bold series of brackets, recessed panels, and Eastlake style tiles in a bird motif. The dining room to the north of the stair hall features a corner fireplace fronted by an elaborate Eastlake style mantel and over mantel which were moved from a residence in Easton. Also on the property is a three-story frame water tower/windmill covered in a combination of plain and imbricated shingles, as well as an early-20th century frame boathouse.
“Llandaff House derives its significance from its Victorian architectural design with a distinctive blend of Queen Anne and Shingle style building forms and Eastlake surface finishes. The hybrid, individualistic design was clearly produced by an as-yet-unidentified architect or skilled designer/builder influenced by the range of architectural styles popular during the late 19th century. The irregular floor plan and multi-faceted roof forms are characteristic of Queen Anne domestic designs, while the universal sheathing of wood shingles and flared base to the second story indicate an influence of the popular Shingle style. By contrast, the bold turned forms in the original front porch, and interior staircase, as well as the carved mantel ornaments, decorative tile hearths, and intricately cast hardware point to the interior designs of Charles Locke Eastlake (1833-1906). The combined architectural influences and resulting exterior and interior designs at Llandaff House are like none other in Talbot County. Augmenting the architectural significance of the property are two outbuildings, a lare-19th century three-story combination water tower and windmill as well as an early-20th century frame boathouse. The house and two outbuildings are set within an expansive park-like yard dotted with mature shade trees and ornamental plants, which constitutes the remnants of professionally designed grounds plan executed by New York landscape architect Thomas Hogan.