Halls of Justice: Headquarters of the Super Friends & Super Squad

While orbiting headquarters were used as the main base of operations for the Justice League encircling Earth-One, and the temporary meeting place for the Justice Society encircling Earth-Two, there were also more accessible earth-bound structures for these teams of heroes. Specifically, these were the Super Friend's Hall of Justice, also occasionally used by the Justice League... and the Super Squad's Brownstone, which they shared with the Justice Society. 

Each of these building were prominently placed in Gotham City. The Society's Brownstone base is well documented and was their primary locale for meetings. As for the Hall of Justice, it fell into disuse following the training of Junior Super Friends Marvin White, Wendy Harris, and the alien Wonder Twins Zan and Jayna. It had been speculated that this wasn't canon.

In fact, references to the Super Friends' existence and their cases was evident in multiple references, both in that team's adventures* and those of its originator, the Justice League**. Like their correlating team on Earth-One, the Earth-Two Super Squad ceased existence following the integration of Power Girl and Star-Spangled in the Justice Society (Robin, although included as a Squad member, was already inducted into the group years earlier). Just as the Junior Super Friends on occasion ventured to the League’s satellite, the Super Squad once rode along with their Society allies in that team’s sky-rocket… which had borrowed components from their scrapped 1951 satellite.

An unspecified time after the dissolution of the Super Friends, Superman encountered various international superheroes whom he first met during a Super Friends mission, when they and their global allies were recruited by Doctor Mist to safeguard the world from various incarcerated supervillians. These various champions from other nations around Earth-One became known as the Global Guardians, a team in action up until the Crisis on Infinite Earths. Those worldwide champions of justice met at Doctor Mist’s mountainous home located in Africa.

After the Wonder Twins completed there training and left Earth-One to venture out into the greater universe from whence they came, the Super Friends training program was discontinued in favor of more integrated training of younger superheroes within the Justice League on their satellite, such as Firestorm as a future member and the second Airwave as an associate. Still later, additional younger heroes such as Steel, Vibe and Gypsy would likewise be groomed by the Leaguers, although this took place at their Detroit factory headquarters.

As such, the Hall of Justice was retrofitted and became the Hall of Heroes, a museum with tributes to the various costumed crusaders. Meanwhile, the Super Squad's former home at the Justice Society Brownstone remained closed off from outside visitors, with various security devices in place to protect the protectors who still met there. Except for the heirs and children of the Society, the future Infinity, Inc. members who broke in during a meeting to petition membership into the team. Which was rejected until they proved themselves later.

* This reference occurred in Super Friends #7 when Marvin and Wendy referred to Superman and Batman working with the Justice League at that same time, while simultaneously Robin was on a case with the Teen Titans.

** This reference was found in Justice League of America #155. During this adventure, the Red Tornado recalled another case in Super Friends #8. An android, originally a member of the Justice Society on Earth-Two who later migrated to Earth-One to join the Justice League... used his vortex-spinning abilities to pierce the time barrier on both occasions.