POVRay short code contest now on

The 5th POVRay short code contest is running. I'm not entering this year but here are my entries from last year, complete with code. I didn't win but had a lot of fun trying.

The Cave:

#macro A(f)finish{reflection{,f}} #end
union{plane{z,20}normal{wrinkles}A(2)}union{sphere{z*22-3,5}A(1)}
union{plane{y,-3}normal{agate.3}A(1)}sky_sphere{pigment{agate scale 3}}

X-Ray:

#macro A(f)cylinder{<9*sin(f),6*cos(f*f),6>,,1,2} #end
union{
blob {A(4)A(5)A(8)A(9)A(0)A(1)A(2)}  
pigment{wood}
finish {reflection{,6}}
}
sky_sphere{pigment{wrinkles}}