|The Water Tower and the Carriage House at Holbrook-Palmer Park are eligible for the National Register under Criterion C, at the local level, as a rare surviving pair of agricultural outbuildings constructed on one of the rural estates developed in Atherton during the late nineteenth century. The Water Tower was constructed ca. 1883 by the prominent San Francisco wholesale hardware dealer Charles C. Holbrook, as part of his "Elmwood" estate. The building was designed in the Second Empire style by San Francisco architect H.C. Macy to match the ca. 1875 Main House that Macy had also been hired to expand and remodel. The Colonial Revival-style Carriage House was constructed in 1897 by Charles Holbrook to replace a three-year-old barn destroyed earlier that year. The Water Tower is significant under Criterion C both for its Second Empire styling, as well as being a rare surviving example of a nineteenth-century tankhouse in Atherton. Most tankhouses were designed in a utilitarian mode, but the Water Tower at Holbrook-Palmer Park was designed to match the nearby "Parisian-style" Main House. The Carriage House is also significant as an example of a utilitarian building type designed in a recognizable architectural style, in this case the Colonial Revival style. It is one of only a handful of remaining barns or carriage houses in Atherton. Located approximately 75' apart, the pair of outbuildings remain essentially unchanged from the late nineteenth century, providing a rare window into a now almost entirely vanished world of nineteenth-century estates of southern San Mateo County. Atherton was once home to several-dozen of these grand rural estates. The twentieth century witnessed the sale, subdivision, and redevelopment of all of these estates. The Holbrook-Palmer Estate was one of the last to go, but unlike the rest its grounds were not subdivided and developed. Instead, it was converted into a park, which at least preserved its open space and its integrity as a single large landholding.