Answer:
I am a path between high natural masses; remove the first letter to get a path between man-made masses.
The more you take away from me, the bigger I shall get. What am I?
I am black within and red without With four corners round about.
I think you live beneath a roof that is upheld by me; I think you seldom walk abroad but my fair form you see; I close you in on every side you very dwelling pave and probably I'll go with you At last into the grave.
I'm really blue but when you see me I'm red. You don't see me too often. I'm there for you if you're hurt.
What is always coming but never arrives?