When the boundaries of a lot are not indicated on the lot, a survey of the lot can be made to determine where the boundaries are according to the lot descriptions or plat diagrams. Formal surveys are done by qualified surveyors, who can make a diagram or map of the lot showing boundaries, dimensions, and the locations of any structures such as buildings, etc. Such surveys are also used to determine if there are any encroachments to the lot. Surveyors can sometimes place posts at the metes of a lot.