I discovered Stygiapolis City by accident this week looking for a historic build on the Krill Empire sim. Instead of old Japanese architecture, I landed in this very large skybox which gives a great vision of what a futuristic vampire city might look like 150 years from now. I especially liked the subterranean builds -- the subway station and older buildings beneath the pavement were very well done.
Highly recommended for a visit and especially for some dark photography. Note that this might be a role play area, but I did not see anyone else here when I visited.