Keystone

Keystone may refer to:

• Keystone (architecture), the piece at the apex of an arch or vault
• The Keystone effect, caused by projecting an image onto a surface at an angle, or by photography at an angle
• Keystone (cask), a wooden or plastic fitting used in ale casks
• Keystone module, a type of data connector mounted in walls and patch panels
• Keystone species, species that have a larger effect on their environment than is purely due to their abundance
• Operation Keystone during World War II
• The Keystone asterism in the Hercules constellation
• Keystone Press Awards, given to Pennsylvania reporters
• Keystone (limestone), a type of limestone quarried in the Florida Keys
• Keystone, a variety of slotted screwdriver blade
• Keystone Initiative, a medical protocol to reduce infection rates

Business

• Digital Keystone, Inc., a developer of digital entertainment software
• Keystone Aircraft Corporation, an early manufacturer of airplanes
• Keystone (beer brand)
• Keystone Camera Company
• Keystone (gasoline automobile), an automobile from Pittsburgh
• Keystone (steam automobile), a steam car from Lebanon, Pennsylvania
• Keystone Pipeline System, a crude oil pipeline from Canada to the U.S.
• Keystone View Company, a US photo agency founded in 1892

Entertainment

• Keystone (video game), a game in the Xbox Live Arcade title Fable 2 Pub Games
• Keystone Kops, a series of silent movies
• Keystone Kapers, a classic Atari game wherein a police officer pursues a thief
• Keystone Studios, movie studio
• The Keystone Berkeley, a theater in Berkeley, California that closed in 1985

Places

• Keystone City, home of the comic book character the Flash

United States

• The "Keystone State", the nickname for the U.S. Commonwealth of Pennsylvania
• Keystone, Imperial County, California
• Keystone, Los Angeles County, California
• Keystone, Tuolumne County, California
• Keystone, Colorado, a town
  • Keystone Resort, the related ski resort
• Keystone, Florida, an unincorporated community
• Keystone, Indiana
• Keystone, Iowa
• Keystone, Nebraska
• Keystone, South Dakota, a town near Mount Rushmore
• Keystone at the Crossing, a business/shopping district located in Indianapolis, Indiana
  • The Fashion Mall at Keystone, a mall located in the Keystone shopping district
• Keystone Heights, Florida
• Keystone Lake, a resort area near Tulsa ,Oklahoma

Railroads

• Keystone Service (Amtrak), Amtrak's current New York-Harrisburg service
• Keystone (Amtrak), Amtrak's former New York-Pittsburgh service
• Keystone, Pennsylvania Railroad's former New York-Washington service
• Keystone (train), a lightweight train built for the Pennsylvania Railroad
• a train operated by Amtrak as part of the Clocker service

Schools

• Keystone School, a private K-12 school in San Antonio, Texas
• Keystone National High School, a private correspondence school