Constructed by Jonah Nicholas Menger to house his soap manufacturing business, this simple yet monumental limestone structure may be the oldest industrial building extant in Texas. The soap works occupied both the basement and the main floor of the structure. The Menger family continued to operate the works until about 1914, producing soap with such catchy names as Alamo Queen and Katy Flyer. It now serves as offices for the apartment complex erected behind it.