Khao Lak Beach, Khao Lak National Park, Phang Nga Province.

The entrance is near the Khao Lak Shrine. You need to buy a ticket to enter the park, and then you can drive in. There are accommodations inside, but it's quite quiet. There is also a wooden staircase leading down to Khao Lak Beach (it's sturdy). Khao Lak Beach might not be suitable for swimming as it's full of rocks of various sizes. Instead, you can take a leisurely walk on the rocks and take some photos.