https://phys.org/news/2019-01-elon-musk-prototype-mars-bound-rocket.html

"Starship test flight rocket just finished assembly at the @SpaceX Texas launch site. This is an actual picture, not a rendering," he wrote.

The prototype built in Boca Chica, along the Gulf Coast of Texas, is nine yards (meters) in diameter—like the future rocket will be—but is shorter.