Read it through once

The harbour lies below me, with, on the far side, one long granite wall stretching out into the sea, with a curve outwards at the end of it, in the middle of which is a lighthouse. A heavy sea-wall runs along outside of it. On the near side, the sea-wall makes an elbow crooked inversely, and its end too has a lighthouse. Between the two piers there is a narrow opening into the harbour, which then suddenly widens.