No, it's not a gnome invasion. If you've spotted micro-sized entryways in the Krog Street Tunnel, along the Beltline, or in a "big old American Elm Tree" on the Freedom Park PATH Trail — among other local places — you've been touched by the whimsy of Tiny Doors ATL. The minuscule doorways are part of an artist cooperative that's striving "to bring wonder to tiny places" with a constantly evolving series of interactive installation pieces, per the volunteer group's website. "With the installation of a door," they write, "what was once a wall or the column of a bridge becomes an entrance to collective creativity and an invitation to whimsy." The initiative is the brainchild of a cake artist and mental health counselor/self-trained artist, and they call their cohorts Tiny Door Guardians. The doors are assembled by a tiny, no-nonsense Rosie the Riveter mascot (per Facebook) with hopes that they evoke "unexpected possibility and chance discovery" for a large audience. The group recently celebrated their 1,000th follower and could barely contain themselves. "We are so excited about all of the doors opening in ATL in 2015," a post reads. "Thank you for being our tiny friend!"