The empty bottle was really a secret lever! You discover a secret tunnel behind the bar, which leads to what looks like a cartography room. On the main desk lies a map with the caption "The New World":
You find a binder with the crests of the four great houses on it. It keeps only two maps yet, which say: "The Great Treehouse, Home of the Springflowers" and "Heartfire Camp, Home of Summer Dawn".
On the windowsill lies a map of Provenance, Adventuria:
On an old chest lies a map with the caption "First expedition into the Sidhe":
In the workstations drawer, you find a map of "North's End" in Adacia,together with the neighbouring "Misty Range":
In the last corner of the room you notice a map of a naval route. It shows the way of a ferry, which collects shipwrecked travelers, and brings them to Haven: