I am not sure what mp this set is from. Ir has a warehouse in the middle and open on the onds of the map. Inside are abot 5 or 6 sets of boxes with thick black lines around them.
Now since it is indoors can some one with leap and climb of flight get on top of these boxes. I konw they are blocking terrain, but what about eleveated?

There is no such thing as elevated terrain indoors, actually. Those boxes are strict blocking terrain, and per the rulebook---

That's in the marvel set either the starter or premiere, I'm not sure - We've always played it as the boxes on the inside are elevated terrain - or, in the case of what HeroComplex said, I guess it'd be hinering terrain, instead...

Not hindering, no. They are blocking terrain. Phasing figures can move through the boxes, but no figure at all, not even a Phasing one, can be on the boxes at the end of movement.