Gallifrey

& despite what some people thought it was not somewhere in Ireland

The Barrier was breached on one occasion by the Sontarans when it was attacked from within. The burnt orange sky casts an amber tint on anything outside the city. There's also vast mountain ranges with fields of deep red grass, the planet also has two suns, one of which rises in the South and makes the mountains shine. Gallifrey is said to have a copper moon, the major city is known as The Citadel which holds the capital of the Time Lords. Within the capital is the Panoption under which the Eye of Harmony (bit like a black hole) is kept. The Eye has all the power for enabling time travel and all timelord Tardise's get their power from it.
Also situated in the capitol is the Matrix, the enormouse extradimensional computer network which acts as the centre for all Time Lord knowledge; It also contains the memories of dead Time Lords. The Citidel is enclosed in a mighty glass dome. Outside the city lay wastelands where outsiders live in less technical tribal communities. This includes the Death Zone where it was used as a gladitorial arena by the first Time Lords putting variouse different species kidnapped from their respective time zones against one another.
Inside the Death Zone stands the tomb of Rassilian, the founder of Timelord society. It's said he developed the technology for time travel that made his people lords of time. He worked with a collegue called Omega who was a Solar engineer, thought killed by Supernova that made the black hole later to be known as the Eye of Harmony. Rossilian harnessed the Eye to provide the energy that powers time travel. He took control of Gallifrey and became the first Lord President. History says that he was a good ruler, while others say he was cruel and opportunistic with ambitions following his friends death. Rossilions tomb is also known as the Dark Tower, there was also a terrorist group running amock called the 'Free Time' group.
Gallifryans are highly telepathic and live for long period's (obviously). Gallifreyans are organised into houses, the Dr's being 'Lungbarrow'. The Dr's real name is gibberish to anyone who isn't Gallifreyian, his reletives soon took to calling him by dirisive nicknames like 'snail' and 'Wormhole'. This was because of the small birthmark he had on the lower part of his chest.
I will add more later, seeing as I can't edit.