For over 20 years The Augusta Heritage Center at Davis Elkins College, in Elkins, West Virginia, has been offering a week long program which immerses participants in Irish culture, music, and dance. I've participated in this program many times, having studied Irish fiddle variously with Kevin Burke, Willie Kelly, and Brian Conway, piano with Brendan Dolan, and Irish dance with Jim Keenan and Mick Mulkerrin. There are around 400 students.
Most people sign up for a particular class which continues through the week.
Classes start at 10 am in the morning, go to lunch hour, and continue in the afternoon. For those who like to participate actively, there are informal groups of musicians and dancers of all skill levels that form spontaneously in various nooks and crannys on campus. These sessions continue all day long and often don't end until 4 or 5 am. I played till 3 am for several nights. I was having such a good time playing fiddle at these sessions, that the time seemed to pass by at double speed.