Most cruises kick off from Iquitos and it's really easy for getting there with immediate flights from Lima. If you take amongst the luxurious cruises you'll in fact begin from Nauta a historic port town suitable to the Marañón River - you'll get there by a lovely drive from Iquitos. https://bookmarkprobe.com/story19418788/the-greatest-guide-to-peru-amazon-jungle-tours