Ardour 2.X had a “Big Clock” window that would display the playhead position in a large, highly visible font that could be easily seen some distance from your computer screen.
In Ardour 3.0, the Big Clock window can be dynamically resized, expanding the font size to any size you feel you need or want for your particular working situation. This can make remote operation via a MIDI or OSC control surface from another room much easier, for example.
Here is the default Big Clock size:
Here it is dramatically resized: