when i was there, there were two buildings down at the lake.
one was a larger building (~2000sqft) which was originally a dorm, then converted to an indoor pool, then back to a regular building again because the pool was too high maintenance. that building was called the SAC (Student Activity Center) and had a tv, some game tables, some arcade machines, and a jukebox. there was a shack next to it (~300-500 sqft) closer to the tennis court which housed landscaping equipment, tennis equipment, fishing equipment, and the sheets laundry. the pavilion at the lake there was never really used for restrictions, it was used as a lounge area on weekends for the student body, and for events like a watermelon-eating contest. the current pool was built somewhere near the lake where the SAC was, but i'm not sure whether or not and which buildings the pool replaced.
there were three other areas that were used more extensively by restrictions: lower left field, where the stream diversion was built and the kids gradually cleared the field further to the "left" of trees to make room for more field space. problem was they didnt count on the field swamping up sans the trees eleven months out of the year. There was a shack with no insulation - just a plywood box with a roof and windows along with a fireplace, that was located by lower left when taking the trail up to RCI, but making a right around the lake. further down that trail was a pavillion in the woods that was used for restrictions also; both structures were there for isolating the bad kids during grandparents day, graduation, dogwood fest, and any other events or emergencies where members of the 'public' were on campus.