nurgakivi

Nurgakivi is an Estonian term meaning "cornerstone" or "foundation stone" used in both literal construction and ceremonial contexts. Etymologically it combines nurga ("corner") and kivi ("stone"). In architecture, a nurgakivi refers to a principal stone placed at a building’s corner or foundation to establish alignment and serve as a symbolic marker for the start of construction. It is distinct from a keystone, which is the central stone of an arch.

As a ritual object, the nurgakivi has long been used in public and private building ceremonies. Laying the nurgakivi often involves an official or dignitary placing the stone, sometimes accompanied by speeches, prayers, or other formalities. The practice symbolizes stability, continuity, and the communal or institutional significance of the structure being erected.

Many nurgakivid bear inscriptions such as dates, names of patrons or builders, and brief dedications. A common accompanying custom is to place a time capsule beneath or within the stone containing documents, newspapers, coins, or other artifacts intended for future discovery. In modern construction the ceremonial aspect often coexists with technical foundation-laying procedures, and the nurgakivi may be decorative rather than structural.

The concept of a nurgakivi appears across cultures under different names and forms, reflecting broader human practices of marking foundational moments in architecture and civic life. Contemporary use ranges from formal state ceremonies to private commemorations for residential and commercial projects.