x-Plummere-block-WEB copy June 10, 2018 1000 × 680 Seattle Now & Then: A Denny Home at 3rd and Union Before the southeast corner of Union Street and Third Avenue was chosen by the feds for Seattle’s new and grand beau arts P.O., the corner was home to the Plummer Block. (We’ve written a feature about this, but for now we cannot find the clip.)