Cannot find ruined portals

I wanted to show what ruined portals looked like to my sister, but I travelled thousands of blocks and I could not find one. So I switched to creative and still could not find one. I loaded up a new world, and still no luck. Another world, and I had to walk 2000 blocks to find one. I thought this was ridiculous and they must be underground. I typed in the commands bar; /locate ruinedportal, and it said something like 'the nearest %feature ruinedportal is at (X, Y, Z), so I travelled to those coordinates, dug all the way down to bedrock on creative, and still could not find a ruined portal. I tried it multiple times.