The Twin Towers were originally set up as an effort to unify the forces of Light and Shadow after the beginning of the Shadow Wars. During these wars, Mordeth, the one-time Forsaken, fought Dark and Light both; and won. It was only after the war began to drag on that the Light and Dark realized that they needed to band together to win. The negotiations between the two sides were mediated by those who had leanings more towards Balance than either Light or Shadow. After the Dark Wars came to an end it became obvious that the world needed some symbol to rally around to begin rebuilding. So three women three women of Power named Danette Galliana, Chani Moonshadow, and Frenzy Rook took on that role, and formed the modern day Twin Towers. The grounds of the Twin Towers are the only place in the world where Light and Dark brush shoulders without coming to blows, and this uneasy truce is strictly enforced by the Triad, those three women.
The Twin Towers Game itself is a Message Board based Role-playing Game and it can sometimes take a lot of time to look at all the activity that has happened in the game in a day. A bit of advice offered to new players is that you find someone who has been in the Towers a while and see if they can give you a quick overview of what has happened up to the point where you joined the game. We are working on putting teams together that will summarize events on a weekly or monthly basis depending on what is happening. Also, once you join the game you can try to keep up with all the posts on the board, but if you run into trouble, only keep up with the ones that directly involve your character--you can always ask some of the other players to explain what you miss.
This is a brief overview of the towers, but I recommend that you visit the Histories page itself, too.