Santorini is a beautiful and romantic destination, perfect for couples looking to enjoy a romantic getaway. Here are some popular activities for couples in Santorini:

1. Watch the sunset: Santorini is famous for its stunning sunsets, and there are many spots on the island where you can enjoy this beautiful sight with your loved one. The villages of Oia and Fira offer some of the best sunset views on the island.

2. Go on a wine tour: Santorini is known for its delicious wines, made from grapes grown in the island's volcanic soil. Take a tour of a local winery, sample some of the island's best wines, and enjoy the beautiful views of the vineyards.

3. Take a romantic cruise: There are many boat tours around Santorini that offer a romantic and unique way to explore the island. You can take a catamaran cruise around the caldera, go on a sunset dinner cruise, or even take a private yacht tour.

4. Visit the beaches: Santorini has some of the most beautiful beaches in the world, with crystal-clear waters and stunning views. Spend a day at the beach with your loved one, enjoy the sun, and go for a swim in the sea.

5. Explore the island's villages: Santorini is full of charming villages with narrow streets, white-washed buildings, and blue-domed churches. Take a walk with your loved one through the villages of Oia, Fira, or Pyrgos, and enjoy the beautiful architecture and stunning views.

In conclusion, Santorini offers a variety of romantic activities for couples, from watching the sunset to going on a wine tour, taking a romantic cruise, visiting the beaches, and exploring the island's villages. These activities will help you create unforgettable memories during your trip to Santorini.