The JLA Secret Sanctuary was a cave in the side of a mountain in Happy Harbor, Rhode Island. Used throughout the Silver Age, the League abandoned it when they moved to the Justice League Satellite. It has since been used by the android Hourman, Young Justice, Doom Patrol and Justice Society of America. Snapper Carr also lived there for a time.
The cave is frequently returned to when the League is in flux, as a rally point when a more current base of operations is unavailable.
The town of Happy Harbor has been attacked by Starro as well as age altered super-villains in the pages of Young Justice.
In Other Media
In the animated series Young Justice, the JLA gives the teenagers the Secret Sanctuary as their new base of operations.
While the Team was out flying in Miss Martian's bioship, Red Tornado learned an emergency alert was triggered at the Happy Harbor Power Plant. The Team investigated and discovered it was being attacked by a new villain named Mister Twister. Their battle caused much property damage to the plant, harbor, and city.
The Team set up a perimeter around Happy Harbor High School to safeguard Dr. Serling Roquette while she completed a virus to neutralize the Fog. Upon an incursion by Cheshire, the Team moved Roquette across the town to the Sandbar internet café while Miss Martian posed as Roquette at another location.
Megan Morse and Conner Kent attended their first day at school.
Megan, Conner and Wally went to the school's Halloween party. They pranked Marvin White, who had hoped to prank his schoolmates with a fake Martian invasion.
With all adults gone due to a spell from Klarion, the Team used the high school as a base to shelter as many children as possible. The older children helped out.