Where are you taken when you are arrested?

It depends on what officer arrests you and where you allegedly broke the law. If you're arrested in a city by a city policeman, you'll probably go to the city's jail. If you're out in the country and you're arrested by a sheriff, you may well end up in the county jail. I believe federal law enforcement has arrangements with counties and cities to house their newly arrested suspects. I just read an article where a person who was arrested for breaking a federal law was remanded to the Marshall's custody - in a county jail.