The Hampshire College Summer Studies in Mathematics (HCSSiM) is a residential program for mathematically talented high school students. It has been running almost every summer since about 1969.
The program is created and currently still headed by, the amazing Professor David Kelly, more affectionately called Kelly by his students. The program is housed at Hampshire College, located at Massachusetts (and NOT New Hampshire).
The program itself consists of lectures, study sessions, maxi-s, mini-s. and has served as the basis for many other similar programs due to HCSSiM's success.