Ah-ha! Yes you may be right.

I assumed the waterfall was to the left of the word 'waterfall' on the smaller tributary stream, but maybe the word is just put anywhere in the locality where there is a bit of space.

If you look a bit further along the burn there are some more black lines with the words 'falls' first on the left of the river and then on the right!

The line cutting across the tributary is in fact part of the O.S. symbol for a run of pylons. (They don't place the actual position of the pylons on the 1:50s, but do on the 1:25s.)

I think they place the descriptor where it has least effect on surrounding mapping.

:slightly_smiling_face: