Nexus

The Nexus is an area that connects multiple hunting grounds. You could call the ocean a nexus as well but if people talk about the nexus they probably talk about the nexus which can be accessed with book 3 pathfinding from the well in the eastern farms.

The Nexus currently contains 3 snells filled with pretty dangerous creatures. You might count more snells but those not mentioned are usually not that dangerous. ;) The first snell you will enter from tc will be a cave that is usually packed with easier Meshras and Jade Arachnoids. Sometimes there might be also Olives. It happened once(?) that there spawned stronger Riptide Meshra as well. Going from there you have another path in the north that leads to another cave usually filled with slime monsters. Those wich can make you stun. You might also see Basalt Greymyrs inside there. This cave has an exit that leads to a well in the Greymyr passes. The cave then has also the connection to a third cave which is probably the most dangerous inside the nexus. It can also be accessed from the first snell when going east. Inside the third snell there are usually some trool'kins of various strengths but it also happens that you find very dangerous creatures like Tearers and Cavern Wurms there. This cave has exits to the Glen nexus (which then leads to Glen Trools, Glen Spiders and Glen Forest) as well as the exit to the shallow Estuary.

Due to the amount and strength of the monsters inside the nexus you should think twice if you want to go inside alone...