**Day 1: Departure from Seattle**
Depart from Seattle and fly to Cancun, Mexico. Upon arrival, transfer to Tulum. Check into your accommodations at the Nest Tulum, a boutique hotel on the beach, known for its beautiful design and excellent service.
**Day 2: Relax and Unwind**
Spend your first day relaxing and adjusting to the tropical pace of life. Lounge on the beautiful white sandy beach, swim in the Caribbean Sea, and dine at your hotel's beachfront restaurant.
**Day 3: Tulum Ruins**
Visit the Tulum Ruins, a well-preserved Mayan site located on a cliff overlooking the Caribbean Sea. Spend the afternoon exploring Tulum’s downtown area (Tulum Pueblo) and try local Mexican cuisine.
**Day 4: Cenote Day**
Explore some of the area's beautiful cenotes. Swim, snorkel or dive in the crystal-clear fresh waters of the Gran Cenote or Cenote Dos Ojos.
**Day 5: Sian Ka'an Biosphere Reserve**
Take a tour of the Sian Ka'an Biosphere Reserve, a UNESCO World Heritage Site. Explore the mangroves, wetlands, and coral reef by boat, and spot local wildlife such as dolphins, manatees, and tropical birds.
**Day 6: Visit Coba**
Visit the ancient Mayan city of Coba. Climb the Nohoch Mul pyramid for panoramic views of the surrounding jungle, and learn about Mayan history and culture.
**Day 7: Beach Day and Spa**
Enjoy a full day of relaxation on the beach. Consider treating yourselves to a couples' massage or spa treatment at the hotel's spa.
**Day 8: Cooking Class**
Join a Mexican cooking class. Learn how to prepare traditional Yucatecan dishes and enjoy the fruits of your labor for lunch.
**Day 9: Explore Cozumel Island**
Take a day trip to Cozumel Island. Rent a scooter or a car to circle the island, stop by the beautiful beaches, and enjoy snorkeling on the coral reefs.
**Day 10: Visit Akumal**
Travel to Akumal, a small town located between Tulum and Playa del Carmen. Here, you can snorkel with sea turtles right off the beach. Spend the rest of your day relaxing on the stunning Akumal Bay.
**Day 11: Yoga and Leisure Day**
Participate in a yoga class at your hotel or a local yoga studio. Spend the rest of the day at your leisure, soaking up your last moments in Tulum.
**Day 12: Departure**
After a leisurely morning, transfer to Cancun International Airport for your return flight to Seattle.
*This itinerary is a suggestion and can be personalized to cater to individual preferences and interests. Remember to respect the local culture and environment during your travels.