Edited for 2 different UTDM-monsters, if I still had access to UnrealEd I'd probably eventually have edited for the only other kind I know of as well.

What we have here is a large map with two symmetrical sides which a large wall in-between them.

They're not exactly "bases" as both open areas have a lot of things in them but no singular individual structure.

The wall itself is massive, with various ways to get across it (above, below, and at ground level) with a couple surprises within it.

I first edited UTDMT (1 titan per team) onto it...

...before eventually doing a UTDMW (2 warlords per team) version as well. Although, in many respects, the UTDMT version can be the most deadly as a Titan throwing boulders in such an open space hits players like bowling pins.

Usual Suspects:
.u - /system
.unr - /maps
png - Pwetty!

Enjoy!
· https://www.mediafire.com/file/prlif5m2pok1mv3/CTF-UTDMT-GreatWall.zip
· https://www.mediafire.com/file/wxuqarv6d5f8svm/CTF-UTDMW-GreatWall.zip