Buildings, including private residences and commercial developments, may be notable as a result of their historic, social, economic, or architectural importance, but they require significant in-depth coverage by reliable, third-party sources to establish notability. Artificial features related to infrastructure (for example, bridges and dams) can be notable under Wikipedia's GNG. Where their notability is unclear, they generally redirect to more general articles or to a named natural feature that prompted their creation, e.g., to an article about the notable road it carries or the notable obstacle it spans.