The treehouse base of Phantom and Friends sits high atop an old oak tree in the Swanson's backyard. A rope ladder serves as the only way up, but there is a zipline that can be used to get back down to the ground. Inside the base, a circular table sits in the middle of the room, with beanbag chairs scattered around. There's a bookshelf and a Toy chest that each hold many interesting things. Currently, a map of the town is taped onto the table, with red X-es drawn over most of the houses on the east side, and green circles around a handful of places across town.
The Phantom and Muse are both sitting on beanbags around the table, looking at the map and waiting for the other heroes to show up now.
The Waterway middle school is the only place in town where a truce has ever held. It's a diplomatic spot, and so Henri and Carol are very anxious to leave the Neutral grounds and begin to fill their evening's quota of Chaos around town.
The building itself is one of the nicer places in Waterway, though everyone still hates it because it's a school. The front of the building is about 5 feet from the main street, and so as children leave for the day usually cars aren't even allowed to drive that stretch of road until all's clear. The bus stop where the two members of the Chaotic Alliance are waiting is on the corner of the street that the school is on, so the bus can actually get to the children it needs to transport.
Jay's house is right across the street from the school, and right next to the park. Honestly, best spot to live for a kid. His front yard faces the school, and from his bedroom (homebase) he can see and monitor the Phantom and Friend's Treehouse base through the window.
Currently, Jay is sitting on his front porch, because the doors to the house are locked. He can't change into costume until his dad gets home to let him in, so for the moment he's stuck as a civilian.