Here's a preview of the overland map (without province borders). It's a swampy area with 4 flavors of gates visible. Clockwise from top left: water, life, blood (the pool of blood at the bottom), astral. The blood gates look different from the other 7 flavors of gate because blood magic is different from the 7 other types of magic in dom3.
(The thing in the middle is just decoration.)
Gameplay-wise, there are five gates of each of the 8 flavors scattered across the overland map. If you step into any of the five pools of blood on the overland map, you are brought to the blood node (which looks like the four nodes in the post above, except blood themed). In the blood node, you can exit through any blood pool. If you stay in the blood node (or any node) too long, you will have bad things happen to you. Depending on which of the .map files you play with (I'll provide 3?) you might also be able to recruit blood mages (other mages for other nodes) in the blood node. The other seven flavors of gates all function the same way.