-Cool Places In GW2
There’s the Wizards Tower, which floats in the air in Kessex, but it’s inaccessible.
It was there since GW1.
Hmm… Not many castle like hangout places, there’s Vigil Keep north from LA, but with limited access.
Dunno other places to hang out, would be LA, Grand Piazza (Lion’s Court)
I rarely do PvP or Hard PvE, unless it’s organized.
Goemm’s Lab might be worth a look:
http://wiki.guildwars2.com/wiki/Goemm%27s_Lab
It’s a huge abandoned Asuran lab high in the sky above Metrica Province. The cool thing is it’s actually visible from the ground if you know where to look, and if you fall (and manage to miss the metamagic safety nets) you can accidentally actually go skydiving back down too!
The entrance is a well hidden overgrown cave / forested area, so that seems to fit what you’re describing as well. Plus, because it’s a jump puzzle, you will occasionally have visitors to hassle. You can follow them around and yell at them to “GET OUT OF MY COOL FORT”. Or like, invite them to tea or something. Might be fun either way.