Q:Dr. Samuel D. Mercer House - The Dr. Samuel D. Mercer House was built in 1885 at 3920 Cuming Street in the historic Walnut Hill neighborhood of Omaha Nebraska United States. Samuel Mercer was the chief surgeon of the Union Pacific Railroad and the founder of Omaha's first hospital.A grand 23-room red brick mansion built in the Queen Anne style the key feature of the home is a three-story square tower that rises above the south side main entrance. The cost of the structure was $60000. Given a choice of categories company, educational institution, artist, athlete, office holder, mean of transportation, building, natural place, village, animal, plant, album, film or written work, the text refers to which one?
A:
Building