A pop-up park in downtown Portland is causing complaints to pop up. The park, on Federal Street between Exchange and Market streets in the Old Port, is being used by the new Press Hotel as an outdoor entertainment space. Adjacent to outdoor seating for the hotel’s restaurant, the park has benches, lighting and circles of outdoor carpeting. The park, which has been dubbed the Federal Street Folly by the hotel’s developers, is open to the public and not restricted solely to hotel guests. In May, the city approved a three-month permit for the park.