612-630 Main (1900): The two story, Mathew's Opera House Block, is the largest building in the district, stretching about half the length of the block. Its facing consists of gray colored brick and masonry materials. At the southern end of the structure, just above the flat roofline, a peaked roof appears that houses the opera house. A stamp metal cornice features brackets and dentils, and below this, lapped and indented brick embellishments are seen. Three types of surrounds adorn the window heads: flat, round arched, and arch stepped. String course, with interruptions by pilasters at intervals, forms the window sills. The majority of second story windows are rectangular in shape and about four feet high and two feet wide. Although not pure in style, the structure design suggests an Italian Renaissance building.