Allegheny River Lock and Dam No. 6 is a historic lock and dam complex located at Bethel Township and South Buffalo Township in Armstrong County Pennsylvania. It was built between 1927 and 1928 by the United States Army Corps of Engineers and consists of the lock dam esplanade Operations Building and two locktenders' houses. The lock measures 56 feet by 360 feet and has a lift of 12.4 feet. The dam measures approximately 20 feet high and 992 feet long. Given a list of categories: company, educational institution, artist, athlete, office holder, mean of transportation, building, natural place, village, animal, plant, album, film or written work, what category does the paragraph belong to?
A:
Building