This link says the site is down for essential maintenance.
https://www.historicenvironment.scot...l-photography/
More explanation is here. Several sites are being worked on.
https://www.historicenvironment.scot...e-maintenance/
"In order to provide the best experience for our users, some of our websites are currently down while we take some precautionary steps around cyber security. This essential maintenance work will ensure that our websites run smoothly and safely for all users."
"We are working on the following services:"
"Canmore
SCRAN
National Collection of Aerial Photography (NCAP)
PastMap
Buildings At Risk Register
Britain From Above
Scotland's Places
We apologise for any inconvenience and would like to thank you for your patience."