Hennessy Hall (The Mansion) is the centerpiece of the campus. This 100-room Georgian-style masterpiece was designed in the 1890s by Stanford White, and replicates a wing in Henry VIII's Hampton Court. Most of its interior decorations (such as staircases and fireplaces) are in Italian marble, worked by Italian craftsmen. Hennessy also holds the chestnut-panelled Hartman Lounge (the former billiard room) and Lenfell Hall, then a ballroom and drawing room, now used for meetings and special events.
Today, Hennessy contains classrooms and administrative offices (see link at right). Visitors to campus also won't want to miss the Italian and Clowney Gardens located along the sides and back of the mansion.