Giant's Causeway cases the horizontal fracture has resulted in a bottom face that is convex while the upper face of the lower segment is concave, producing what are called "ball and socket" joints. The size of the columns is primarily determined by the speed at which lava from a volcanic eruption cools. The extensive fracture network produced the distinctive columns seen today. The basalts were originally part of a great volcanic plateau called the Thulean Plateau which formed during the Paleocene. According to legend, the columns are the remains of a causeway built by a giant. The story goes that the Irish
Secret of the Cave raw footage was shot. The cave, a central part of the film, was not discovered until 2 or 3 days before the scheduled shoot. It was discovered by a crew member, walking during a break. Secret of the Cave Secret of the Cave is a 2006 student film by the School of Visual Art and Design at Southern Adventist University. The film is an adaptation of the 1920 children's story of the same name by Arthur S. Maxwell (also known as "Uncle Arthur"). It was released on DVD in September 2007 and is distributed by First Look Studios in conjunction