I used to play around with Google SketchUp for architectural design, but Minecraft in some ways is a lot more fun to design things in.

This is a building I designed in Minecraft for artistic purposes. Around a 48m central spine of glowstone, there is a 3m×3m spiral staircase with a 45° incline, with each 360° turn of stairs being 8m higher than the previous level, for six levels of stairs in all. And railing the staircase is a spiral of dirt, on which I planted 48 oak trees from the top down. The result is the appearance of a tower ringed by a garland of green foliage, and a crown of even fuller, bushier green foliage which are actually tall trees unencumbered by any layers of dirt above them. The glowstone spine is necessary to provide adequate light for the saplings to grow - Minecraft not having the most realistic lighting physics. After I built the first prototype of this tower, I realized it was not only technically a pagoda, but it also resembles a torch towering into the sky - but instead of a crown of fire, there is a crown of foliage.

I'm not 100% certain if this is permitted by the Acceptable Upload Policy - I tried to ask on the forums, but no one would respond to my questions. And since this is a structure of my own design, I decided to go ahead and upload it. I hope it's alright.