If you arrive by plane, bear in mind there's a Colombian entry tax of 20,000 pesos. If you're arriving from another country, you'll get your entry stamp at the airport.
Make sure you talk to your GP about anti-malarial treatments.
On arriving in town, you may be surprised by the ranks of motorbikes and motor-taxis.
Leticia's an odd town. Isolated and on the border, it's not particularly interesting in itself, but it's known as a departure point for trips to the Amazon. Most hotels offer jungle tours that last between 1 to 5 days.
Leticia's also the town from where you can cross the Amazon River. If you want to tour Peru or Brazil by travelling down the river, take a moto-taxi to Tabatinga, Leticia's Brazilian sister town. You can withdraw Brazilian Reals from a Brazilian cashpoint, drop by the market to buy a hammock, which you'll need for the crossing, and then head to the port to buy at ticket for the boat.
We recommend you keep the same moto-taxi, as if you don't you'll find it hard to find another in Tabatinga and we have to admit that we didn't feel very safe in town.