A niche in classical architecture is an exedra

Exedra

In architecture, an exedra is a semicircular recess or plinth, often crowned by a semi-dome, which is sometimes set into a building's facade. The original Greek sense was applied to a room that opened onto a stoa, ringed with curved high-backed stone benches, a suitable place for a philosophical...

 or an apse

Apse

In architecture, the apse is a semicircular recess covered with a hemispherical vault or semi-dome...

 that has been reduced in size, retaining the half-dome heading usual for an apse. Nero's Domus Aurea

Domus Aurea

The Domus Aurea was a large landscaped portico villa, designed to take advantage of artificially created landscapes built in the heart of Ancient Rome by the Emperor Nero after the Great Fire of Rome had cleared away the aristocratic dwellings on the slopes of the Palatine...

 (AD 64–69) was the first semi-private dwelling that possessed rooms that were given richly varied floor plans, shaped with niches and exedras; sheathed in dazzling polished white marble, such curved surfaces concentrated or dispersed the daylight.

The word derives from the Latin nidus or nest

Nest

A nest is a place of refuge to hold an animal's eggs or provide a place to live or raise offspring. They are usually made of some organic material such as twigs, grass, and leaves; or may simply be a depression in the ground, or a hole in a tree, rock or building...

, via the French niche. The Italian nicchio for a sea-shell may also be involved, as the traditional decoration for the top of a niche is a scallop

Scallop

A scallop is a marine bivalve mollusk of the family Pectinidae. Scallops are a cosmopolitan family, found in all of the world's oceans. Many scallops are highly prized as a food source...

 shell, as in the illustration, hence also the alternative term of "conch" for a semi-dome

Semi-dome

A semi-dome, also called a "half-dome", is the term in architecture for half a dome , used to cover a semi-circular area. Similar structures occur in nature.-Architecture:...

, usually reserved for larger exedra.

In Gothic architecture

Gothic architecture

Gothic architecture is a style of architecture that flourished during the high and late medieval period. It evolved from Romanesque architecture and was succeeded by Renaissance architecture....

, a niche may be set within a tabernacle

Church tabernacle

A tabernacle is the fixed, locked box in which, in some Christian churches, the Eucharist is "reserved" . A less obvious container, set into the wall, is called an aumbry....

 framing, like a richly-decorated miniature house ("aedicule"), such as might serve for a reliquary

Reliquary

A reliquary is a container for relics. These may be the physical remains of saints, such as bones, pieces of clothing, or some object associated with saints or other religious figures...

. The backings for the altars in churches ("reredos

Reredos

thumb|300px|right|An altar and reredos from [[St. Josaphat's Roman Catholic Church|St. Josaphat Catholic Church]] in [[Detroit]], [[Michigan]]. This would be called a [[retable]] in many other languages and countries....

") can be embedded with niches for statue

Statue

A statue is a sculpture in the round representing a person or persons, an animal, an idea or an event, normally full-length, as opposed to a bust, and at least close to life-size, or larger...

s. Though a niche in either Classical or Gothic contexts may be empty and merely provide some articulation and variety to a section of wall, the cult origins of the niche suggested that it be filled with a statue. One of the earliest buildings which uses external niches containing statues is the Church of Orsanmichele

Orsanmichele

Orsanmichele is a church in the Italian city of Florence...

 in Florence, built between 1380-1404. The Uffizi

Uffizi

The Uffizi Gallery , is a museum in Florence, Italy. It is one of the oldest and most famous art museums of the Western world.-History:...

 Palace in Florence(1560-81) modified the concept by setting the niche within the wall so it did not protrude. The Uffizi has two dozen or so such niches containing statues of great historical figures. In England the Uffizi style niches were adopted at Montacute House

Montacute House

Montacute House is a late Elizabethan country house situated in the South Somerset village of Montacute. This house is a textbook example of English architecture during a period that was moving from the medieval Gothic to the Renaissance Classical; this has resulted in Montacute being regarded as...

(c. 1598), where there are 9 exterior niches containing statues of the Nine Worthies

Nine Worthies

The Nine Worthies are nine historical, scriptural and legendary personages who personify the ideals of chivalry as were established in the Middle Ages. All are commonly referred to as 'Princes' in their own right, despite whatever true titles each man may have held...

. In Fra Filippo Lippi

Filippo Lippi

Fra' Filippo Lippi , also called Lippo Lippi, was an Italian painter of the Italian Quattrocento .-Biography and works:...

's Madonna (illustration, right) the trompe-l'oeil niche frames her as with the canopy of estate

Baldachin

A baldachin, or baldaquin , is a canopy of state over an altar or throne. It had its beginnings as a cloth canopy, but in other cases it is a sturdy, permanent architectural feature, particularly over high altars in cathedrals, where such a structure is more correctly called a ciborium when it is...

 that was positioned over a personage of importance in the late Middle Ages and Early Modern Europe. At the same time, the Madonna is represented as an iconic sculpture who has "come alive" with miraculous immediacy.

Expanding from its primary sense as an architectural recess, a niche can be applied to a rocky hollow, crack, crevice, or foothold. The sense of a niche as a clearly defined narrow space led to its use describing the relational position of an organism's species, its ecological niche

Ecological niche

In ecology, a niche is a term describing the relational position of a species or population in its ecosystem to each other; e.g. a dolphin could potentially be in another ecological niche from one that travels in a different pod if the members of these pods utilize significantly different food...

.