I wasn't sure if I was going to pull this off or not but I'm pretty happy with the end result. This is the front gate to a neolithic hill fort, like the ones you'd see at Maiden Castle in Dorchester, UK. Hill forts had a super complicated system of ditches and revertment that created this "wave-like" effect in the terrain.

For mechanical purposes, treat these like difficult terrain. You might even require a DC 10 Strength (Athletics) check to climb up over the rises since they're pretty steep.
This set comes with grid and no-grid versions in day and night.
Map Specifications
Maps created in DungeonDraft using Forgotten Adventures' assets.
For personal use only, no commercial usage is allowed.