Hua Hin has a few great viewpoints which give you a great panoramic view perfect for pictures. The most popular one is the Hin Lek Fai.
This viewpoint has multiple lookout points and is located three kilometres from Hua Hin, giving it a nice viewpoint angle with the ocean in the background. The only downside of Hin Lek Fai is the monkeys. The time that I visited Hin Lek Fai, the monkeys were destroying cars and even rented motorbikes. A great alternative viewpoint is Wat Khao Takiap. You can climb the large rock by stairs and on top of that rock, you will find a temple and a viewpoint that in both directions. For me, it was much easier the reach and we did not get harassed by any monkey.