About the sub-category "Binnen Amstel", i see at least the name as a problem. Allmost noone (even in Amsterdam) knows what this is, everyone knows this waterway/river as "Amstel". And the few people who think they know "Binnen Amstel" have varying definitions, the line could be drawn at the Blauwbrug or at the Magere Brug or at the Amstelsluizen or at the (outer) Singelgracht.
On the other hand, i see, with the large number of photos, some use for sub-categories for the Amstel river. I would suggest:
- Amstel (Amsterdam-Centrum) (that is Binnen Amstel in the broadest sense),
- Amstel (outer Amsterdam),
- Amstel (Amstelland) (outside/south of Amsterdam).