The last one your talking about might be glen onoko falls area of the lehigh gorge, it's pretty far from the dam though. It's the take out for the lower section of the lehigh river. It's just outside jim thorpe, you could probably get there from allentown in less than a half hour.
Large train bridge maybe 40 or fifty feet, VERY popular for jumping and swimming. Large area of rock beach nearby to hang out(where all the rafts are on the weekend) and a huge cave in a rock wall that used to be the train tunnel I guess. Lots of parking and hiking in the area too. Actually there are three waterfalls up a hiking path across the tracks, biggest being about 60 or 70 feet, the creek is small though so none of those are jumpable.