DAVOR-
That's great news! I share your pain upgrading to SSL.
Last year, I had been planning to work with Cesium and geolocation.
When I finally got around to testing geolocation in January, I learned using geolocation in Google's Chrome was going to force me to upgrade my GoDaddy development server to SSL.
That was an unfortunate extra annual expense for the certificate, and I lost a week of Cesium javascript development time to updating my WordPress site.
I'm glad it's behind me, and that the pain of upgrading the website is over. But I haven't had much free time to get back to my geolocation feature in Cesium, so your post caught my eye.
I'm afraid I will never visit your country in person, but thanks for your virtual tour of Castles, and good luck embedding the Cesium 3D map with your Location!.
-Jon "Left Gully"