Gianlorenzo Bernini, baldacchino, St. Peter's, Rome, 1624-1633. Gilded bronze, approx 100' high.
Baldacchino- A canopy on columns, frequently built over an altar. (a similar term is...)
Ciborium - A canopy, often freestanding and supported by four columns, erected over an altar; also, a covered cup used in the sacraments of the Christian Church. (Gardner)