Here's the story behind those swings popping up around San Francisco

Swings have cropped up all over the city courtesy of #Swingbombsf. Swings have cropped up all over the city courtesy of #Swingbombsf. Photo: Instagram @swingbombsf Photo: Instagram @swingbombsf Image 1 of / 14 Caption Close Here's the story behind those swings popping up around San Francisco 1 / 14 Back to Gallery

Dozens of rope swings have been installed all over San Francisco by a guerilla group that wants to help bring a sense of joy and wonder to the city's denizens.

The group, #SwingbombSF, put up 50 rope swings all over San Francisco starting last weekend. They haven't released a complete list of their locations, because where's the fun in that?

The swings did draw the ire of some at the Recreation and Parks Department, who expressed concern that the swing's haven't been evaluated for safety by the city. Operations Manager Dennis Kern told ABC7 that since the swings are not permitted, the Recreation and Parks Department has no choice but to take them down when they encounter them.

Click through the gallery above for pictures of the swings.

In a note to blogger Broke Ass Stuart, the group said the swings, which are hand-painted and individually numbered, were engineered and placed to be safe and secure.

"People often call SF an adults' playground," the note read. "Well, we're turning it into a real pop-up playground this weekend!"

"We hope that our "swing bombing" will bring more joy, wonder to the people of SF. Something that anyone and everyone can enjoy," it continued.

Some of the swings have since been cut down by park rangers, Instagram commenters note, but others are still up and swaying, waiting for people to find them.

Filipa Ioannou is an SFGATE staff writer. Email her at fioannou@sfchronicle.com and follow her on Twitter