For the next several centuries, it remained the de-facto
center of what little government the wizarding world had, as well as a school
for the children of Hogsmeade and any others of magical skill who wished to
attend. Because of the difficult journey and the need to know it existed in the
first place, that was more or less exclusively the wealthy, and when all the
kids of the wealthy also go to school together, it only solidifies the class
system. 

With the school rapidly growing buildings were constantly
being built to accommodate the students, arriving to start establishing
particular floors for subjects, houses and overall organisation of the school.
many secrets remain in hogwarts but an overall ground floor map is shown
below. 

Many charms enchant Hogwarts so that Hogwarts is hidden to Muggles. Also Wizards and witches cannot Apparate or Disapparate to, or from within, Hogwarts (with an exception to the Headmaster).