Where does a person go after attaining Nirvana? After attaining Nirvana, what happens to the person(conscious) after death? 

Does the person cease to exist?

If not, does the person go to some peaceful place?
In one sense he continues just as we do. Once he attained nirvana under the Bodhi tree, the Buddha carried on teaching for another 50 years. It was only on the death of his physical body that he underwent parinirvana, that is to say final release. However this just pushes the question on from nirvana to parinirvana.

The question of what happens to an enlightened being after death is one of the unanswered questions i.e. does the Tathagata (Buddha) exist after death. The Buddha refused to address metaphysical issues such as these. He teaches one thing and that thing is liberation. He views other issues such as this, the nature of the universe, the nature of the 'soul' as a distraction.

It's not to say that this isn't a good question but it is one that is deliberately unanswered by the Buddha. As such I'm probably not going to be able to do it either.

It's the answer of no answer

NOTE

This answer is based on Theravada teachings and is not the stance of all Buddhist schools. Other answers here will be from different perspectives and should be considered along with this answer.