From June through October, humpback whales arrive in the warm waters off Puerto Lopez to mate and calve. They have traveled thousands of kilometers from Antarctica, following the currents up the Pacific coast, and they gather here because the bay protects their young and the krill feeds the mothers. Tour boats leave the pier every morning during the season, and captains have developed an ear for the difference between the random slap of a wave and the breach of a 40-ton animal. Songs of the males, which can last twenty minutes, vibrate through the hulls. Puerto Lopez made its name as the departure point for Isla de la Plata, the so-called poor man's Galapagos with its blue-footed boobies and frigate colonies, but in the whale months the town takes on a different character, quieter somehow, as if everyone were listening for something.

Machalilla National Park begins just outside town and stretches along 55 kilometers of coastline, protecting one of Ecuador's last tracts of coastal dry forest and a slice of Pacific ocean that functions as a national marine sanctuary. The park headquarters sits one block behind the Puerto Lopez plaza with a small museum and free admission. Ten kilometers north, Playa Los Frailes opens onto one of the continent's most extraordinary beaches: white sand curving between green cliffs, clear water without a single building in sight. Mototaxi from town costs six dollars round-trip. Buses drop visitors at the park entrance for fifty cents, and the three-kilometer walk to Los Frailes passes two smaller beaches and several viewpoints where the coastline unfolds in sequence.

A few kilometers inland from Puerto Lopez, the archaeological site of Agua Blanca preserves the remains of the Manteño culture, a coastal civilization that flourished between roughly 800 and 1532 AD. The Manteño were expert navigators whose balsa rafts sailed as far as Mesoamerica, and they left behind stone seats, ceremonial platforms, and carved figures that now occupy the site's small museum. The village takes its name from a pre-Incan sulphur-water pool where visitors can bathe in water that smells faintly of eggs and reputedly heals everything the doctors cannot. The Salango Museum, further south along the coast, holds an extraordinary collection of Manteño pottery and spondylus shell work. Spondylus, the thorny oyster, was the indigenous currency of the Pacific coast, more valuable than gold and traded as far as Peru.

The town stretches along a curve of beach, and in the evenings the Malecon fills with people eating ceviche at the cabanas and watching the sun go down over the Pacific. Empanadas cost fifty cents from the food carts a few blocks back from the shore. Seafood restaurants along the beachfront serve three and a half to ten dollars a plate. Three Italian restaurants have appeared over the years, evidence of the slow accretion of expat tastes and backpacker economies. Pilsener, the local beer of choice, goes for a dollar fifty for a 600-milliliter bottle. Salsa and reggae blast from the cabanas late into the night. The bus terminal sits a mile north of town on the coastal highway. Tuc-tuc mototaxis charge a dollar to bring new arrivals into the center, and during the whale season every hostel in town is full.