I play Minecraft occasionally with a friend on a shared server called The Land of Make Believe.

Coordinates

Mesa City (1470, 80, -3540) (185, 63, -450 nether) Alexandria (-330, 80, -740) (-52, 77, -124 nether)

Building notes

Current tower: cylinder is 12 radius, the ellipsoid on top is 14 (i.e. would be a 28 block sphere, but I'm using half-slabs). I've just built level 18, so the next is 19.

Building reference and inspiration

• @swordself_mc is a good reference for block colour ramps and simply decorated buildings.
• Plotz Modeller — a tool for generating ellipsoids and other shapes.