import solids;

size(8cm,0);

currentprojection=orthographic((2, 1, 2));

revolution r = cylinder ((0, 0, 0), 1, -10, X);

r.draw();
draw("$x$",O--X,Arrow);
draw("$y$",O--Y,Arrow);
draw("$z$",O--Z,Arrow);

triple z=relpoint(relpoint(r.skeleton().longitudinal[0],0.5)--
                  relpoint(r.skeleton().longitudinal[1],0.5),0.5);
// Project Label onto plane through point O with normal cross(u,v):
// Label project(Label L, triple u, triple v, triple O=O,
//               projection P=currentprojection)
label(scale(2.5)*rotate(180)*project("This is not a cylinder",X,Y,shift(z)*(0,0,1)));