Colony 9 itself is a safe area, a village divided into three major parts. The first area of Colony 9 is the Market District, which is attached to the main bridge that connects to the colony. Here you can find the Store, a large number of wandering citizens, and a bit more than a third of the named NPCs in town. There is also an Ether Forge here, though it isn’t working just yet. Several of the NPCs in the area will give you quick tutorials or informationals on how to do certain things, so keep poking them.
The front part of the Market District is a circular courtyard around the Ether Light. Off to the left are an alley and a street- the alley leads up some stairs to a long balcony that sits above the street, and includes a bridge into the large warehouse on the left side of the street. Behind the warehouse is a ledge you can jump off of to reach a small hidden area- here you can find one or two other citizens, and a red light- the Spanner. At the end of the street is the bridge to the central junction of Colony 9, but to one side is a small cul-de-sac that you will want to visit during day and night.
The central part of the colony is a set of three bridges connected by a Landmark at the middle. There are occasionally interesting people wandering across the bridges, but most of them are in the three areas.
If you turn right from the Market as you cross the bridges, or if you enter Colony 9 from the mountain path with the small park at the end, you’ll find yourself in the Residential District. This area is full of interesting quests and trades, and has a landmark of its own as well. Of note here are a crashed Mobile Artillery unit that will soon be important, a large number of named NPCs, and another red light- the Key.
Opposite the Residential District is the Military District. This part of Colony 9 is full of Defence Soldiers, some of whom have quests. It is also where Shulk’s workshop is located, and where you can get in contact with ‘Square-tache’.
Of additional note is the main entrance to Colony 9, near the Market District- in front of this area is a large house that sits outside of Colony 9's walls. This is Dunban’s House, and because of that it will be important several times in the near future. Also, behind it is a red light- the Wedding Ring key item.
Finally, there is the little park at the top of the mountainside path. While the stairs are full of wild animals and considered part of the environs, the park is a part of Colony 9 itself. While there is nothing of note there in the way of objects or villagers, it also becomes important shortly.