North Stack (Welsh: Ynys Arw, meaning "rugged island") is a small island situated just off Holy Island on the north-west coast of Anglesey.

North Stack can also refer to the headland opposite the island. This is the site of a redundant fog warning station, comprising a number of buildings, including the Trinity House Magazine, built in 1861, where shells for the warning cannon were stored. These buildings now house a bird watching observatory, giving a view of South Stack lighthouse across Gogarth Bay, and the studio of artist Philippa Jacobs. The Precambrian quartzite cliffs of this headland, including North Stack Walls and Wen Zawn, provide some of the most well-known rock climbs in Britain, such as "A Dream of White Horses", "The Cad" and "The Bells! The Bells!"

North Stack is the small island at the end of Gogarth Bay

Trinity House Magazine, North Stack

Rock climbing at North Stack

Coordinates: 53°19′20″N 4°41′01″W / 53.3223°N 4.6836°W / 53.3223; -4.6836

Brian Stack (born August 18, 1967) is an American actor, comedian, and writer best known for his sketch comedy work on all three Conan O'Brien late-night talk shows, previously working on Late Night with Conan O'Brien and The Tonight Show with Conan O'Brien, and on O'Brien's current talk show, Conan on TBS.

Stack attended Catholic schools from grades 5-12, graduating from St. Viator High School in Arlington Heights, Illinois. He earned an undergraduate degree from Indiana University, where he had worked at their radio station. He began doing improvisational comedy, or improv, in 1987 at the Ark Theater in Madison, Wisconsin, while attending graduate school at University of Wisconsin–Madison, where he earned his Master’s degree.

Stack became a sketch writer on Late Night with Conan O’Brien in 1997, and served as a writer, actor and editor on the show and after O'Brien's move to the Tonight Show in 2009. Stack played many recurring characters on the show, most notably those clad in anachronistic or elaborate outfits, and was known for playing many characters with long beards and mustaches, such as God, Zeus, Socrates, Gandalf, and The Interrupter. Stack makes occasional appearances on the Tonight Show, such as when he played an NRA spokesman who intimates violence to accomplish his agenda.