Iquitos is the world's largest city unreachable by road - accessible only by plane or boat. Located on the Amazon River, it was the rubber boom capital in the early 20th century. Explore the floating Belen Market where vendors sell from canoes, the historic rubber baron neighborhood with Casa de Fierro designed by Gustave Eiffel, and the vibrant Malecon boardwalk. The city is the main gateway for Peruvian Amazon tours and jungle lodge stays.