Dating back to 1885, Ambrose Hall has been the central focus of the campus since the school was founded. Originally housing all academic functions, including classrooms, chapel, gymnasium and dormitories, it was last restored in 1977 and placed on the National Register of Historic Places.  The first step was the documentation and assessment of existing conditions and history in the form of a Historic Structure Report. The team carefully surveyed the condition of every window, nearly 500 of them, and every square foot of the exterior walls and roof. A bell dating from the 19th century was discovered in the original central tower, waiting for a clock that was never installed. Upon completion of the report, the restoration project began. This included removal of 1950s era remodeling of the distinctive mansard "Second Empire style" slate roofs and replicating these roofs based on slates discovered on site and with historic photographs. Damage to the windows was determined to be extensive, so new windows replicating the original design and details were installed. The central clock tower was restored, with new slate roofing, window details and a clock. Massive damage was discovered on many sections of the original brickwork as well as at the original sandstone foundation walls, and these were repaired with matching materials. The original 1885 cornerstone, which had nearly eroded away, was also replicated.