I been to a lot of "secret places" so not so new to me, but theres a couple more spots in Jangan which are really awesome. If only i could upload images it would be easier.
try to go north at jangan on the swamps till u hit the dike separating the river and the swamp. i forget the coordinates but sure thing you can get down from the swamp somewhere and travel beneath this river. enjoy snorkeling. make sure you have a return scroll if you cant get out.
There are 2 spots to get in to the river that runs east to West. 6 spots to get in the river that runs north and south. The mountain south of the bandit stronghold can be climbed from either side in 2 general areas. The mountain south of that has one access point just a bit west of the southern most bridge. The mountain between the 2nd and 3rd bridges from the north can be climbed in 2 places. One at it's south most tip and the other part way up on the west face. The mountain between 3 and 4 can also be climbed in 2 places. The south east corner and another near the north west. The mountain between the jangan ferries can also be climbed in 2 spots. The east side of the east ferry path also has 2 climbable sections. There are some odds and ends outside of those like getting behind the water fall in the ch'in tomb or getting on the other side of the east moat. Plus there are some sections of wall you can run along on the upper decks that take you to hidden spots.
yeh you can also travel in the sea at the ferry, got to the ferry on the right and go to the rocks on right hand side before you take the ferry over to dowang yellow, and you can get to the sea.
wth dude?!?! why are you giving away haulf of the secrets to the forums! (thats not all of them) but anyway i already know about this and i am sure a lot of other ppl already know about it