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Delphi was encircled by a rolling temperate rain forest and was located fairly close to a mountain range. Before the Fall of the Twelve Colonies, the city boasted a large spaceport and a military base. One of the tallest structures in Delphi was the Telamont Building. Another major landmark was the Delphi Museum of the Colonies; among the items at the museum was the Arrow of Apollo, an artifact that held clues to the general whereabouts of Earth, home of the legendary Thirteenth Tribe (TRS: "Colonial Day," "Kobol's Last Gleaming, Part I").
In the less urbanized outskirts of the city, the Delphi Convalescent Institute served patients suffering from mental illness for more than sixty years prior to the fall of the Colonies (CAP: "The Imperfections of Memory"). The Delphi Union High School was also located in this more forested area (TRS: "Resistance").
Prior to the attack, Kara Thrace owned a studio apartment in Delphi. Overlooking a parking lot, the apartment was in complete disarray, having inoperative air conditioning, faulty heating, and a broken toilet. The living room was littered with paintings of her own creation, including one particular painting on the wall (complete with a poem) and a tiny cache of cigars. Thrace was not very enthusiastic about the apartment (TRS: "Valley of Darkness").
After the Fall
Following the Cylon attack, Delphi, which was not directly targeted by nuclear weapons and therefore remained mostly intact, was used by the Cylons as a base of operations. The Cylons gradually re-settled Delphi - the humanoid Cylons appropriated apartments, restored the landscaping, and opened a restaurant and other facilities. The Delphi Convalescent Institute was temporarily converted into a farm for reproductive procedures with human women (TRS: "The Farm"). After being resurrected, Sharon Valerii returned for a time to the apartment she had lived in prior to the fall of the Colonies (TRS: "Downloaded").
The Caprica Buccaneers pyramid team survived the Cylon attack while undertaking high-altitude training near Delphi. They relocated to the Delphi Union High School and operated a resistance to the Cylon occupation from that location (TRS: "Resistance").
A Cylon posing as Sharon Valerii and Karl Agathon reached Delphi after two months of traveling the surrounding countryside, intending to steal a ship and leave Caprica (TRS: "Flesh and Bone," "The Hand of God," "Colonial Day").
After seeing visions of a city on the planet Kobol, President Laura Roslin overrode Commander William Adama's plans and persuaded Kara Thrace to take a captured Cylon Raider to Delphi in order to recover the Arrow of Apollo. Successfully jumping to Caprica, Thrace landed near the Delphi Museum and managed to retrieve the artifact ("Kobol's Last Gleaming, Part I," "Part II"). Temporarily stranded on Caprica, Thrace returned to her old apartment with Agathon to collect an old jacket, a personal memento, and keys to her old military truck (TRS: "Valley of Darkness").
Delphi, as with the rest of the Colonies, was allegedly abandoned as the Cylons left to find the last remnants of humanity in order to find a way to co-exist with them (TRS: "Lay Down Your Burdens, Part II").