丘

Hi,

I'm having some trouble figuring out exactly what丘 is describing in this sentence.

This is a description of a fortress:
西方以外のすべての門は、塔や望楼などに守られ、北と南、各門の近くには、段々状に丘 を切り取って、砲兵陣地が設けられていた。

I had always thought of 丘 as a piece of naturally elevated land, though this sentence confuses me a bit. What does '丘' mean here? I'm leaning for one of these three.

1. 丘 refers to a portion of the fortress wall built taller than the rest
2. It's a portion of the wall built on top of a mound, thus elevating it
3. It's really just a big mound (supposedly behind the gates/walls)

切り取って gives me the impression the hill was already there and they just shaped it to fit their needs.

Veering slightly off topic, but Mike's post made me think of Maori hill forts. This seems to describe something of a similar nature (段々状 = terraced see related term 段々畑)