Two hours south of Tarapoto on a steep, twisting road that drops down past the Huallaga river crossing at Cumbaza, Laguna Azul is a roughly oval lake of about 350 hectares set among low jungle hills. Locals call it Laguna Azul for the clarity of its water; the lake itself is officially Lago Sauce. You can swim straight from the dock at any of the string of small lakeside lodges that line the shore — the water is warm and clear enough that most visitors end up staying longer than planned. Kayaks, paddle boards, and peque-peque canoes are available for hire; a slow loop along the shoreline takes you past a few small villages, grassy beaches, and sheltered coves backed by forest.
Most visitors stay one or two nights rather than attempt a round trip in a single day — the road in is time-consuming and the afternoon light on the water is reason enough to stay. Combi vans and cars-for-hire depart from Tarapoto's centre each morning; organised day tours include the boat crossing of the Huallaga river, which adds a bit of adventure to the journey. The best months to visit are May through September, when rainfall is lower and the lake road is less likely to become muddy.
The lodges range from simple cabaña-style rooms on the water to slightly more comfortable family guesthouses with hammock decks. All serve food; fresh fish from the lake is the thing to order. There are no banks or ATMs in Sauce village, so bring cash from Tarapoto.