Beast Building Server has long been gone but their incredible maps still exist and TT25 is one of those maps. TT25 is the most popular of their maps and is very well made taking advantage of techniques such as VISBlock. The Map itself is huge starting with a huge open field then a spanning underground train rail system that connects the maps huge underground rooms. The map is one of the best build maps I have ever played on.
This map uses simple textures and shapes but these allow for a low lag huge build map with lots of possibilities.
This map was built by Wild Will and was built for the purpose of use on the Beast Builder Server which no longer exists. I was given permission by Wild Will to post this map on GarrysMod.org.
The only server currently running TT25 is the UnitedBuilders.Webs.Com Building Server.