Kayak to Cueva de Neptuno and Swim the Inner Lagoon from El Portús

Set out from Portuskayak in El Portús, Región de Murcia, Spain, and spend a full day paddling along the wild shoreline of the Bay of Cartagena to reach the hidden Cueva de Neptuno. This nine-hour guided trip blends sea-kayaking, a wild beach stop at Cala Aguilar, and a technical descent into a vaulted sea cave with an inner marine lake—an unusual stitch of water and vertical access that turns a coastal paddle into a full-spectrum adventure.

The route begins with a practical skills briefing and gear fitting at Portuskayak, then an hour-long paddle across turquoise, wind-swept water toward Cala Aguilar. The beach is a quiet white-sand cove where you can eat, hydrate, and swim while guides prepare the kit for the cave approach. Access into Cueva de Neptuno is decided by on-site conditions and uses either a zipline or a controlled rappel; both methods require coordination, balance, and confidence on exposed rock. Inside the cave a large skylit chamber opens over a tranquil marine lagoon ringed by weathered rock and sculpted formations—one of the trip’s signature tableaux for swimmers and photographers.

Expect 2–3 hours of exploration in the cave system: moving between ledges, floating in emerald water, and studying unique coastal geology. The guides speak English and Spanish and lead small groups through safety protocols and route choices. Participants should be able to paddle for roughly 50 minutes, swim, and manage steep, uneven terrain; minimum age is eight years when accompanied by an adult.

What makes this experience stand out is the combination: a paddle along Cartagena’s rugged coast, a private-feel beach hour, and an interior cave lake reached by techniques more often seen in climbing trips. The flora is Mediterranean scrub; seabirds and occasional gannets patrol the cliffs. The Cueva de Neptuno’s chamber—a skylit, water-filled cavern—feels both ancient and immediate, carved by the sea and time.

Practical notes: the trip runs seasonally (peak June–September), has a moderate difficulty rating, and requires non-sedentary fitness. Bring swimwear, sunscreen, shoes you can get wet, and an attitude for hands-on adventure. Portuskayak manages logistics from the meeting point at Portuskayak in El Portús; groups require a minimum of six participants and tours may be rescheduled for adverse weather. For travelers based in Cartagena, the beach and cave make an unforgettable counterpoint to the city’s classical and naval heritage—an active day where sea and stone meet.

Bookings are handled through the Portuskayak reservation system; check availability for your date and expect a safety briefing before launch. Photographers should use waterproof cases and straps; children eight and older join with adults. The route’s rhythm—paddle, beach, vertical entry, and cave time—makes this nine-hour day varied and efficient, ideal for travelers looking for a full-day coastal challenge.