Adding Orkney to the NC500 - worth the detour?

Has anyone added Orkney as a side trip from the NC500? Thinking of taking the ferry from Scrabster to Stromness. How many days should I allow?

Absolutely worth it. We did 2 nights on Orkney and it wasn't enough. Skara Brae, the Ring of Brodgar, St Magnus Cathedral - there's so much history. Allow 3 days minimum.

The Italian Chapel alone is worth the ferry crossing. And the scapa flow wreck diving if you're into that. Book the ferry well in advance though, it fills up fast in summer.

We skipped Orkney on our first NC500 and regretted it. Went back specifically for it and spent 4 days. Different vibe to the Highlands but equally special.