County Museum and Library (Royal Institution of Cornwall)

The County Museum and Library, also known as the Royal Institution of Cornwall, is a building originally constructed as a savings bank in 1845 by architect Philip Sambell for the Trustees of the Truro Savings Bank. It features a granite ashlar front and an asbestos slate roof, complete with a central pediment and parapet. The building has a large rectangular plan with wings on the sides and rear, and it includes a central entrance hall that leads to a very large stair hall with an imperial staircase that has a balcony on all sides.

In a classical style, the building stands two storeys high and has a symmetrical five-window front. It is characterized by a plinth and is articulated by giant Ionic pilasters that divide the bays, with three central bays that are slightly projected forward and topped with a triangular pediment. The central entrance features a distyle Doric porch with a Doric entablature and an elliptical-arched doorway with a fanlight, which has a 20th-century door. Other openings have shallow elliptical arches above 20th-century horned sashes, with the first-floor windows featuring glazing bars.

Inside, the museum retains many interesting features, including a large central hall that is illuminated by a glazed roof, which has a key-pattern ventilator over segmental ribs and ceiling cornices adorned with modillions. The imperial staircase leads to a gallery supported by large moulded brackets, and the interior also includes moulded architraves and a rear lunette over pairs of Ionic columns, as well as panelled ceilings with moulded ribs in the side galleries. This building is recognized as a competent classical composition by the notable Truro architect Philip Sambell.