Leticia sits at a point where three countries meet without a single bridge between them. Colombia, Peru and Brazil converge here, and the river — not the road — carries every arrival and departure. No highway connects Leticia to the rest of Colombia. The town is reachable only by air or by water, which explains why the Puerto de Leticia functions less as a dock than as a terminus. The settlement was founded in 1867 as San Antonio, a Peruvian outpost on the left bank of the Amazon. It passed to Colombia in 1922 under the Salomón-Lozano Treaty, then became the flashpoint of the brief Colombia-Peru conflict of 1932. That inheritance still shows in the architecture: low, tin-roofed buildings raised on piles, built to survive an annual flood pulse that can lift the water line by ten metres between the dry and wet seasons. Amazon trips from leticia begin against that backdrop of contested, waterlogged borders. The surrounding department of Amazonas covers roughly 109,000 square kilometres and holds fewer than 80,000 people. Much of it is titled indigenous resguardo. The Ticuna are the largest group, with communities such as Puerto Nariño and Macedonia reachable by peque-peque and fast launch downstream. Their language is a linguistic isolate, unrelated to any neighbouring family. Yagua and Cocama settlements share the same stretch of river. Tours amazonas desde leticia therefore move through inhabited territory, not empty wilderness — a distinction the region's guides insist upon. The ecology is measured in superlatives that are literal rather than decorative. The Amazon basin discharges around 209,000 cubic metres of water per second. Pink river dolphins, the Amazon's *Inia geoffrensis*, surface in the same channels where the giant water lily *Victoria amazonica* spreads leaves two metres across. Isla de los Micos, the island commonly folded into a Leticia Amazon river tour, holds a dense population of introduced squirrel monkeys. Upriver, the Tarapoto lakes near Puerto Nariño form a Ramsar-designated wetland recognised in 2018. What gives the place its present weight is scientific rather than scenic. Leticia hosts research stations and monitoring programmes tracking deforestation, mercury contamination from illegal gold dredging, and manatee recovery. Visitors buying amazon trips from leticia tickets are entering a working laboratory of the tropics. The Ticuna dance masks, the flooded várzea forest, the black-water igapó — each belongs to a system still being described.