Area to explore in undercity/xuang skyway

Hiya, I've got a problem, there's this little bit on the map, that was explorable only thru undercity, but a few updates ago Undercity has gotten it's own map and you don't appear to move on the world map...
Is it still possible to explore this little bit? And if so, how?

Theres a huge thread in the Canthan Explorer League that can help you with that.

Yeah, but the thread was made before ANet added a map to undercity.....

The undercity map has nothing to do with exploration.

Whoops, seems like I've encircled the wrong place, here's the right one



It has. Even tho it and Xuang shared the same map, there was this bit that was only explorable by hugging a wall in the undercity, but now since undercity has gotten it's own map a few patches ago, i don't know if this is still possible to explore. Can anyone help me ? >_>