This one's pretty unusual ;-)
What looks like an arrow scrawled with a marker pen is in fact the shadow of a mast with a triangular frame at the top with the IKEA brand written on each of the three sides. And no, adjusting the tilt down to ground level won't let you read it ;-)

No Sign or Logo Visible. 41.8371 12.5929

In fact, they've dismantled it now, so (unless it's only temporary and they re-erect it) the shadow may have disappeared on the next update of this part of the world... (added Jan 07)