I made a topic like this a few weeks ago, and I got a few people to help, but I lost the topic and the people. :(
Anyways, I'd like to build a really big tower for roleplaying and other different types of TDMS. I already have some plans for it.
It'd be called Silver Tower or something like that..
For the total baseplate, it'd be a good 256 by 256 surface area, basically four 64 by 64 plates each direction, with two 16 by 16 plates on each side, giving it a good look. It'd be a good 10 64 by 64 cubes tall, about 640 total. After the completion of the tower we'd build a small but detailed city around it. Here's a picture of the initial layout.