The 4th is a good chunk of what used to be medieval Paris, and you'll find a lot left from that time on both islands and in the narrow streets of the lower Marais. Meanwhile there's lots that's contemporary to look at especially at the Centre Georges Pompidou where you'll find a lot of the very best contemporary art.
At night the 4th has several of the most active bar scenes most travelers will have ever seen, including the lower Marais district which is sometimes known as gay Paris although there are no shortage of bars catering to straight singles or a mixed crowd, or, in the early evening, families.
