Thanks to a mysterious guerrilla organization, it just got a lot harder to walk the streets of San Francisco without feeling your inner child come out. As SF Weekly reports, a group called Swing Bomb SF has installed 50 swings from trees and structures around the city.

As the anonymous group writes in their Instagram bio, their goal was to turn San Francisco into a "pop-up playground." The swings were hung in secret over a weekend in locations like Lombard Street, the Embarcadero, and the Tenderloin district. With no indication of where the swings came from besides the hashtag #SwingBombSF drawn on the bottom of each swing, they seem to be there to invite the young and young-at-heart to stop whatever they're doing, sit a while, and allow themselves to have fun.

While San Francisco residents seem to be enjoying the playful additions to the landscape, San Francisco Recreation and Parks is likely less happy to see them. Though Swing Bomb SF claims to have engineers on board who tested the structural integrity of each swing, they were still installed on city property without permission. As long as they're still up, Swing Bomb SF is accepting Instagram photos tagged with @swingbombsf and #swingbombSF to share on their account.

[h/t SF Weekly]