About an hour's drive north of the beach resorts of Máncora and Punta Sal is Tumbes, the last city on the Peruvian side of the Peru-Ecuador border. Tumbes played a major role in Peruvian history: it was here that Pizarro first saw the riches of the vast Inca Empire in 1528, which he would return to conquer in 1532. In the past, tensions were high—it wasn't until 1941 that Tumbes became part of Peru after a military skirmish.
Tensions are now minimal. Hot, muggy Tumbes is unlike anywhere else in the country. The coastal desert that has defined the Pan-American Highway all the way to Chile is no more, and in its place is a landscape that is decidedly more tropical, with mangrove forests and banana plantations. For most visitors Tumbes is just a transit point to or from Ecuador or a quick stop before an early flight. The city has few attractions or attractive places to spend the night, but for those with the urge to explore, there are several excellent national parks, and there is plenty of inexpensive shellfish plus an atmosphere you will not find anywhere else in Peru.
If you find yourself crossing the border at Aguas Verdes, be extra aware of your personal belongings. Like many border towns, it has its fair share of counterfeit money, illegal goods, and scams to get money from foreigners.