Spirits are everywhere in Luang Prabang and interaction with these spirits forms an innate part of the local culture. The belief in spirits goes back in the mists of time, pre-dating the adoption of Buddhism as the religion of the Lao and has persisted despite several attempts by rulers to extinguish these supposedly "primitive" beliefs.
In the Lao world view spirits or Phi (ຜີ) inhabit the trees, the ground, fields, rocks, places of water and even machinery such as cars and buses. These phi are abundant but amorphous and nameless. If not treated with respect phi can be malevolent but fortunately they are usually easily placated by simple offerings of food & drinks. The Lao make offerings to the phi frequently and the sharp eyed visitor to Luang Prabang can see evidence of this on almost every street.
The most obvious evidence of this is the spirit houses or Ho Phi (ຫໍຜີ), little wooden houses mounted on a pole found out the front of most buildings, sometimes fitted out with little figurines and other artefacts. When fresh land is broken to build any building, it is necessary to placate the phi that live within that land. Therefore a new house, the Ho Phi, is built for them and a ceremony held to entice the phi to move into this new residence. Subsequently the residents of the land will make regular offerings of food (Often fruit or sticky rice) & drinks (Bottles of water or soft drink, opened and with a straw inserted ready to drink). Incense sticks will be burnt each morning at the front of the Ho Phi to show respect to the phi heuan (ຜີເຮືອນ), the spirit of the house.
In Luang Prabang it is also very common to see little banana leaf cones decorated with marigolds known as van (ຫວ້ານ) together with little balls of sticky rice placed as offerings on top of walls or on balconies. These offerings are made particularly on Buddhist holy days, and many street sellers can be seen making and selling these colourful van.
If taking a boat along the Mekong River one will notice that all the boats have some plants placed at the front bow of the boat. Again these are not mere decoration, but offerings to the river phi to keep the boat and its occupants safe on their journey. It is also said that one should not wear red when travelling by river as this colour may upset the phi of the river.
Another important spirit site found in all Lao towns is the City Pillar or Lak Meuang. This is a sacred post which marks the location of the city's guardian spirit and is erected at time of founding the town or city. In large cities these days the Lak Meuang may be a very elaborate shrine, as is the case in Vientiane. However, in Luang Prabang it remains as a very simple shrine, almost hidden away in an unremarked side street across the road from Vat Ho Xieng. It was originally located near Vat That Luang but was later moved to its current location (I have not yet been able to ascertain the date of this move).