National Register of Historic Places property types

Buildings, as defined by the National Register, are structures intended to shelter some sort of human activity.

The term building, as in outbuilding, can be used to refer to historically and functionally related units, such as a courthouse and a jail, or a barn and a house.

If a nominated building has lost any of its basic structural elements, it is considered a ruin and categorized as a site.

[2] According to the Register definition, a historic district is: "a geographically definable area, urban or rural, possessing a significant concentration, linkage, or continuity of sites, buildings, structures, or objects united by past events or aesthetically by plan or physical development.

"[2] For example, the largest collection of houses from 17th and 18th century America are found in the McIntire Historic District in Salem, Massachusetts.

Significant alterations to a property can damage its physical connections with the past, lowering its historic integrity.

NRHP-listed sites often possess significance for their potential to yield information in the future, though they are added to the Register under all four of the criteria for inclusion.

Structures differ from buildings, in that they are functional constructions meant to be used for purposes other than sheltering human activity.

Structures that have lost their historic configuration or pattern of organization through demolition or deterioration, much like buildings, are considered ruins and classified as sites.

They included: preserved historic vessels, shipwrecks and hulks (those ships not afloat but not submerged entirely); documentation (logs, journals, charts, photos, etc.

); small craft (less than 40 feet long, less than 20 tons of displacement); artifact collections (fine art, tools, woodwork, parts of vessels, etc.

TCPs include built or natural locations, areas, or features considered sacred or culturally significant by a group or people.

However, some scholars argue a site need not be associated with a Native American cultural group to qualify as a TCP for the purposes of the NRHP.

[10][11] The National Park Service, through the U.S. Department of the Interior, provides specific guidelines for the evaluation and documentation of traditional cultural properties.