housemaids' tower. The stables are similarly designed to present the appearance of a fortress gatehouse. On the wider estate are located an extensive Home Farm and a range of gate lodges. Not all of these structures have appealed to architectural critics. Mowl and Earnshaw, in their study of lodges and gatehouses Trumpet At A Distant Gate, are particularly dismissive of Hopper's Grand Lodge, and of Hopper more generally. The lodge is condemned as "misapplied historicism" while Hopper himself is censured as a model for the then-coming generation of Victorian architects, his career demonstrating how to "gain a whole world of rich commissions by eclectic dexterity, and still lose his own soul." Listing designations The castle is a Grade I listed building. Its Cadw listing designation describes it as "one of the most important country houses in Wales; a superb example of the relatively short-lived Norman Revival of the early 19th century and generally regarded as the masterpiece of its architect, Thomas Hopper.” Other listed structures within the estate, all of which are Grade II with the exception of the Grand Lodge which is designated Grade II*, include: the Grand Lodge itself, the Port Lodge and its walls, the Tal-y-bont Lodge, the walls to the flower garden, the relocated remnants of the original medieval chapel, a bothy and its walled garden, an estate house, the estate manager's house, the estate kennels, nine buildings at the home farm, and the wall surrounding the park. Gardens and grounds The castle grounds are an example of the Victorian style of gardening, with specimen trees, rhododenra, and much planting. A conifer was planted by Queen Victoria and another by the Queen of Romania. There is a substantial home farm. The gardens contain a large underground reservoir, constructed in the 1840s and with a capacity of 200,000 gallons. Its purpose is uncertain, it may have been for use by the castle’s in-house fire brigade in the event of a fire. The park is listed Grade II* on the Cadw/ICOMOS Register of Parks and Gardens of Special Historic Interest in Wales. The castle and its grounds are part of the UNESCO World Heritage Site, the Slate Landscape of Northwest Wales. Other Railway Museum The Penrhyn Castle Railway Museum is a narrow gauge railway museum. The Pennant's slate quarry at Bethesda was closely associated with the development of industrial narrow-gauge railways, and in particular the Penrhyn Quarry Railway