Look at the paragraph beginning: the place seemed entirely land locked

quite buried among trees tells us that Jim cannot see everything.

The place was entirely land-locked, buried in woods, the trees coming right down to high-water mark, the shores mostly flat, and the hilltops standing round at a distance in a sort of amphitheatre, one here, one there. Two little rivers, or rather two swamps, emptied out into this pond, as you might call it; and the foliage round that part of the shore had a kind of poisonous brightness. From the ship we could see nothing of the house or stockade, for they were quite buried among trees; and if it had not been for the chart on the companion, we might have been the first that had ever anchored there since the island arose out of the seas. There was not a breath of air moving, nor a sound but that of the surf booming half a mile away along the beaches and against the rocks outside. A peculiar stagnant smell hung over the anchorage—a smell of sodden leaves and rotting tree trunks. I observed the doctor sniffing and sniffing, like someone tasting a bad egg.