text: Copper has played a role in architecture for thousands of years. For example, in ancient Egypt, massive doors to the temple of Amen-Re at Karnak were clad with copper. In the 3rd Century B.C., copper roof shingles were installed atop of the Lowa Maha Paya Temple in Sri Lanka. And the Romans used copper as roof covering for the Pantheon in 27 B.C.
  Centuries later, copper and its alloys were integral in medieval architecture. The doors of the Church of the Nativity at Bethlehem (6th century) are covered with plates of bronze, cut out in patterns. Those of Hagia Sophia at Constantinople, of the 8th and 9th century, are wrought in bronze. Bronze doors on the Aachen Cathedral in Germany date back to about 800 A.D. Bronze baptistery doors at the Cathedral of Florence were completed in 1423 A.D. by Ghiberti.
  The copper roof of Hildesheim Cathedral, installed in 1280 A.D., survives to this day. And the roof at Kronborg, one of northern Europes most important Renaissance castles that was immortalized as Elsinore Castle in Shakespeares Hamlet, was installed in 1585 A.D. The copper on the tower was renovated in 2009.
  For years, copper was reserved mainly for public institutions, such as churches, government buildings, and universities. Copper roofs are often one of the most architecturally distinguishable features of these structures.
  Today, architectural copper is used in roofing systems, flashings and copings, rain gutters and downspouts, building expansion joints, wall cladding, domes, spires, vaults, and various other design elements. Simultaneously, the metal has evolved from a weather barrier and exterior design element into indoor building environments where it is changing the way commercial and residential interiors are decorated.
  In the 21st century, the use of copper continues to evolve in the indoor environment. Its recently proven antimicrobial properties reduce pathogenic bacterial loads on such products as handrails, bedrails, bathroom fixtures, counter tops, etc. These antimicrobial copper-based products are now being incorporated into public facilities (hospitals, nursing homes, mass transit facilities) as well as in residential buildings because of the public health benefits. (For main article, see: Antimicrobial copper-alloy touch surfaces.)