Baths of Beautiful Helen: Secret Sea Cave Thermal Spa Cruise

Discover a hidden sea cave with a certified thermal spring on a cruise from Isthmia. Snorkel in the Saronic Gulf, enjoy a fruit salad and wine, and relax on the shaded upper deck.
Escape the crowded commercial spots and immerse your senses in a hidden paradise of ancient history and certified physical wellness. This exclusive 4-hour coastal cruise takes you to the legendary Baths of Beautiful Helen, a secret thermal oasis where state-certified therapeutic waters gush from a rocky sea cave—offering the ultimate, revitalizing natural spa experience in the Saronic Gulf.

Depart from the Port of Isthmia and enjoy a scenic 30-minute sail aboard a modern 17-meter glass-bottom vessel. Arrive at an untouched, rugged coastline completely inaccessible by land vehicles. To protect the serenity of the landscape and ensure a high-end personalized experience, this cruise is strictly limited to 30–35 passengers maximum.

Upon arrival, under the strict supervision of a dedicated swim guide, guests are divided into two small, comfortable groups of 15 to explore the majestic, open-roof sea cave. Inside, pure, thermal water bubbles directly from the earth. The water is surprisingly fresh, crisp, and clean, creating a magnificent blending of warm and cold currents.

Equipped with complimentary high-quality masks and short snorkeling fins (ideal for easy swimming and protecting the marine flora), spend 15-20 minutes inside the cave and snorkel around a vibrant, untouched reef. For your absolute peace of mind, a calm, shallow beach is located right next to the cave for easy resting.

After your revitalizing thermal spa session, set sail for the serene and peaceful Siderona Bay. Drop anchor for a second, fully relaxing swim in warmer waters. Then, relax on the comfortable shaded upper deck and indulge in a freshly prepared, ice-cold seasonal fruit salad and a traditional local sweet treat, accompanied by refreshing beverages and local wine. Return to the port feeling completely revitalized, clean, and younger.

To guarantee availability book as soon as possible. Early booking is worth consideration especially if you planning the trip during high season like public holidays or weekends.

This excursion you can cancel with no cost up to 24 hours before the start of the trip. If you cancel it after 24 hours or not show up on the excursion you will still be charged the full price of the activity. Being late on pick-up or departure will be considered as not showing up.