The Riddler | 115 followers on LinkedIn. The Riddler is a Champagne bar in the heart of San Francisco’s Hayes Valley, occupying a tiny window-lined corner cafe space that dates back to the late 1800’s. We have over 100 Champagnes by the bottle and dozens of sparkling wines by the glass to choose from: old and new, traditional classics and unusual discoveries, by the glass and by the bottle (or magnum or 9L). At the center of our space is an old wooden backbar that we’ve lined with a collection of vintage Champagne buckets and glassware that we’ve picked up at flea markets and estate sales over the last decade.