You can see Mounts Erai and Manureva from the observation platform. They’re the island’s highest peaks. The village of Moerai and its Protestant church are below you. Steep limestone cliffs in between are pockmarked with hidden chalk caves. While a small airplane is gliding toward the little airport’s landing strip on the northern tip. Your eyes aren’t on the beautiful island, though. You’re focused on the dark spots in the turquoise water.

The dark spots are humpback whales. Each summer, from July to October, they travel to Rurutu. The island’s nearly unbroken fringing coral reef, which lies just offshore, is a protected spot. It’s where the massive male baleen whales—known for their knobby heads and long pectoral fins—compete for dominance. The dark gray whales breach and slap the water. They sing, grunt, and groan. They’re showing off for the females the whole time. It’s an amazing dance to see up close.

Rurutu is the northernmost island in the Austral archipelago. Like most of its neighbors, the island is volcanic and covered with a dense green jungle. Citrus, coffee, lychees, and, of course, taro grow well here. White-sand beaches and that fringing reef ring the island. It’s the caves that make this island unique, though. The concealed spots are filled with stalactites, stalagmites, and huge ferns. Early inhabitants lived in these caves. The small villages, where traditional woven baskets and patchwork bedspreads are still made, didn’t appear until much later. They, as well as the whales, are finally drawing tourists to this rarely visited island.

You took an hour-and-a-half flight from Papeete, Tahiti (355 miles north) to Rurutu. Hotels and resorts haven’t been built on the island yet. That’s a good thing. But it left you anxious about your accommodations. Your worries dissipated as soon as you arrived at Vaitumu Village. The family-owned pension is new. It’s home to seven coral-stone bungalows with bright bedspreads and solar-heated water. Fresh flowers are on your bed no matter what time you pop back into the room. There are an open-air restaurant and a long pool, as well. But, most importantly, it’s just steps from the beach and those breeding whales. Rurutu already seems to be unlike any other French Polynesian island you’ve ever visited.