1. Grandmother and Grandfather Rocks, known as Hin Yai and Hin Ta in Thai, are natural rock formations located on the southern coast of Koh Samui, a popular island in Thailand. These rocks have become a famous tourist attraction due to their unique shape which resembles male and female genitalia.

Hin Yai, which translates to \"Grandmother Rock,\" is a large rock formation that resembles the shape of female genitalia. It is made up of smooth granite and juts out into the sea. Hin Ta, meaning \"Grandfather Rock,\" is a nearby rock formation that resembles male genitalia, with a protruding shape.

These rock formations have become iconic landmarks on the island and are often visited by tourists who wish to see the unique natural formations and take memorable photographs. The rocks are located on the shore, offering scenic views of the ocean and nearby beaches.

2. The Grandmother and Grandfather Rocks are accessible to visitors all year round. There is no official working time as they are part of the natural landscape. However, it is recommended to visit during daylight hours for better visibility and safer access to the rocks.

As for contact information, there is no specific phone number available for the rocks as they are not managed by any individual or organization. They are freely accessible to the public.

3. There is no entrance fee or ticket required to visit the Grandmother and Grandfather Rocks. However, it is common for local vendors and souvenir shops to be present in the area, where visitors can purchase snacks, refreshments, and souvenirs.

Transportation to the Grandmother and Grandfather Rocks can be arranged through various means. The most common option is to hire a taxi or tuk-tuk from your accommodation on the island. Alternatively, you can rent a scooter or car and drive to the rocks yourself. It is located approximately 16 kilometers from the popular tourist area of Chaweng Beach.