The twin bays are separated by a narrow isthmus.

Without major coastal defence measures the narrow isthmus would probably have long since been destroyed.

This triangular area connected to dry land at the base by a narrow isthmus and protected by a moat (inner moat).

The island grew, engulfing several smaller islands nearby, and eventually becoming connected to the mainland by a narrow isthmus.

The fjord nearly splits the peninsula into two halves, with the western half separated from the nunatak in the east by a low, narrow isthmus.