Yeah Swamp and STW would be good to check out in this respect. Swamp does expose coordinates but it does lots of other things too, including the aforementioned beacons.
Games like SBYW, the tombhunter remake, and Perilous Hearts use a four direction viewer. and SBYW and TH add a camera to that.
Sarah and the Castle of Witchcraft and wizardry, along with GMA Tank Commander use a 360 degree object browser, while Lonewolf can do a circular audio scan that has different sounds for objects around you, similar to Swamp but slower.
You can remove coordinates and even exact distances from this and just use directions, or at least reduce the viewing range.
A similar function in a minimap format kind of like Three D Velocity would work too.
Or you can go bare bones like Treasure Hunt and Entombed, and simply use sound cues to point out corridor openings, doors, ETC. Maybe spice it up a bit like Sarah does with large rooms having more echo when further from the walls ETC. A (have I been here before?) function, some player placeable markers that announce when you walk over them again, even an auto turn to door/opening feature if you wish, similar but not exactly like A Hero's Call's turn to object keys.
It's all up to you and these are just concepts. I'm sure you can modify or build on them as needed for your particular game...