Interstellar was presented in both 70mm 5 perf and IMAX 70mm 15 perf, though it was shot on 35mm and IMAX 70mm.
There are various lists of existing 70mm 5 perf theaters but I know a lot of them are defunct or rarely used. I think Interstellar only was shown in about a dozen or so places in that format over the whole US. Reportedly Tarantino is refitting 50ish theaters to play the film for the 70mm run. This is no small challenge since the equipment is quite old and the number of people who are still alive that can rebuild or operate it is pretty small.