Terrain chunk loading and unloading

Hi! I am working on a procedural landscape thing. It loads the world with the marching cubes algorithm in chunks (16x16 grids). I want to have the world load chunks strategically like shown in the gif (top-down view). In the gif the player is looking towards the top of the screen. Therefore the algorithm would load the chunk on the top first (to generalize it, the algorithm should load the chunks in the direction the player is facing first. I think limiting it to the 4 directions north, south, east and west would be best (and easiest)). I just need the chunks to be sorted in a list based on this concept I think. Then I can load them in that order. Can anyone help me achieve this or lead me on the right path? I don't have a lot of experience with algorithms. Also, I am not sure what the best way to load and unload chunks are. Do I just disable them or what? I mean, the player can build and stuff so if I were to destroy them I would have to save the data somewhere. Any help would be greatly appreciated. ![alt text][1] [1]: /storage/temp/178027-chunk-loading.gif