The Amazon River runs through The Valley of the Amazon down to the Lake, past Heald Wood and the High Moor on one side and High Topps and Kanchenjunga on the other. The road to Dundale goes up the valley. Atkinson's Ground, Nook Farm and Tyson's Farm are all up the valley.
The lower reaches of the river goes through meadows, past Beckfoot and the Warriner's Low Farm at Watersmeet. Above Beckfoot and the Beckfoot Coppice which are on the right bank of the river, there is a lagoon with water lillies; Roger thinks they may be octopuses so it is called Octopus Lagoon (SA21, PM9). While the Great-Aunt is at Beckfoot the Amazons make a harbour for Scarab called Picthaven in the lagoon (PM14).
The road around the Lake crosses the river at Udal Bridge, a wide-arched stone bridge which they pass under when going up river. They hurry under it in case the GA is driving round to the head of the lake and happens to see them together (SD25).
Greenbanks is between the Amazon River and High Topps, and between Watersmeet and Tysons:
- ... looking back down the valley from half way up the steep slopes of Greenbanks (PM24)
- Greenbanks ... we were up there yesterday. High Topps ends just about there ......... Beyond Greenbanks the valley opened out a little (PP7).
- Mrs Tyson says of the fire .... but when it comes to Greenbanks ye'll not hold it (PP34)
When the Swallows and Amazons go overland to Kanchenjunga; they looked down into the valley of the Amazon ... they could see the flash of water here and there in the green meadows far below them, and away to the right, under the foot of a wooded ridge, they could see a long ribbon of pale reeds that widened suddenly on either side of a little glistening tarn ... "That must be the lagoon ... Beckfoot must be just round the corner of those woods" says John (SD23). Further up towards Halfway Camp, they had been scrambling up beside the tiny mountain beck that was now all that was left to remind them of the river far below them in the valley (SD27).
The Amazon River is based on the River Crake according to Hugh Brogan  and Christina Hardyment  , although the Crake flows out of Coniston but the Amazon flows into The Lake. Allen Tarn a pool in the River Crake just after it flows out of the Lake became the Octopus Lagoon. Cyril Ransome, Arthur’s father, used to fish in the River Crake.