A city found on several maps and featured in the Megathrust Article, which states that an earthquake caused the city to sink into the sea. On the BHAM Map it is called "Old Seattle" and appears as a landmass west of Bellevue, across Lake Washington, while on the Bellevue Map, it is called "Seattle" and appears as a cluster of islands to the west of Bellevue. One can then assume that Lake Washington and the oceanic bay have merged together over time, likely due to flooding that occurred after the earthquake.
A bridge can be crossed to reach the island holding the Seattle Memorial (featured on the Seattle Card), which seems to be a statue of part of the Space Needle. In the ocean surrounding this island are the rest of the Seattle Islands (mostly northward/northwestward), which hold several artifacts and are reachable by swimming.