Niche (architecture)

A niche in classical architecture is an exedra or an apse that has been reduced in size, retaining the half-dome heading usual for an apse. Nero's Domus Aurea (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.