Yesterday the girls and I visited the Sultan Qaboos Grand Mosque. It was the 3rd time for me and the 2nd time for Nadya. We went when she visited in 2019. However Yelena had not been yet.
It is the only mosque open for non-moslims and it is an incredible site.
There are gardens, prayer halls and 5 minarets. The one in this picture is the tallest.
There are many websites with a lot of info about this mosque. I like the link below as you can tour the mosque from behind your computer. And when you scroll to the bottom there is some info too. https://sultanqaboosgrandmosque.com/