That is a spirit house placed auspiciously in a tree. It is built in the form of a miniature temple mounted on a pedestal. They’re actually seen everywhere you go in Cambodia – inside hotels, internet cafes, offices, factories, shops, and all houses in Cambodia have one.The idea is that it provides shelter to wandering spirits which could cause problems for the people if they are not appeased.
The above spirit house, on the other hand, was taken in Kep, a coastal town in Cambodia. It is for neak ta (local guardian spirit) because it’s left here by the tree and facing the sea . According to the locals, the trees and the sea are protected by neak ta. Hence, cutting the trees surrounding the spirit house is strictly prohibited. Here’s a paragraph I lifted from Andy Brouwer’s blog post on neak ta:
The cult of Neak Ta rests in nature. Local spirits inhabit mountains, rivers, trees, rice paddies, swamps and forests; even an odd shaped tree or rock can be inhabited by a local spirit. For Khmer, they are living, watching spirits of the land. Several types of supernatural entities are believed to exist, that make themselves known by means of inexplicable sounds or happenings. They are frequently asked for protection, as some are compliant, others are merciless against those who fail to show proper respect.
Visit Andy Brouwer’s blog to read more of neak ta and other Cambodian folklores.