Ban Gioc Waterfall - permit required?

First post :)

I arrived in Cao Bang today and would like to go see the Ban Gioc waterfall either tomorrow or the day after. I tried to find some more recent posts about whether or not a permit is needed but was unable to find anything from 2012.

Problem is, when we checked out of our hotel in Hanoi this morning, we were anxious to get to the bus station early so didn't realize that the hotel didn't give us back our passports and only realized when we were already on the bus ride to Cao Bang.

So I would like to know:
1) is a permit still required to see Ban Gioc?
2) if a permit is or is not required, will they ask to see your passport?

Thanks in advance