Spider Man, captain america suit Chewbacca and Predator were all spotted by Scarborough today as a two day long Sci-Fi convention kicked off. A Spider Man character walks along the seafront, leaving a passerby confused. So you can visit artists alley , you can visit small press , you can hit the exhibit floor. The three-day event is held at the Washington Convention Center where attendees can expect a variety of stars, games and booths to enjoy.