The sound of waves that make us so relax....
Seeing trees and green plants have a powerful ability to relieve your stress down. It's not really looking for parks with shady trees, because some images or photos with green scenery also has similar capabilities.
Based on the true research at some hospitals in Netherland in 2012, many patiens shown by natural-green posters that able to stay away from stress.
Alright, actually I wanna show you some pictures that perhaps able to solve it. This pictures was taken by me 
You also do not need all the way to the beach to calm your mind anyway. Seeing images in the form of sea views was also allegedly have a psychological effect that can affect you to calm down.