Starting Saturday, the Emerald Necklace Conservancy is celebrating its 20th anniversary with a citywide exhibition of multiple fog sculptures, including two locations in Jamaica Plain. Japanese artist Fujiko Nakaya has created five fog installations along 12 different Boston neighborhoods. The fog sculptures are, "...shape-shifting, pure water forms invite visitors to immerse themselves in the art, experience nature anew, and appreciate the vital role of the Emerald Necklace in our city’s history, present, and future." The sculptures will be on view every day, hourly from dawn to dusk, from August 11 through Halloween. Nakaya calls fog “the most generous medium” and has created fog sculptures all over the world.