"What a beautiful scenery!" - may sound correct to most of us but it's grammatically wrong.
"What beautiful scenery!" - may sound awkward but it's actually correct.
Do you know why?
So, we cannot say '...a scenery' or 'sceneries'. ;)
*It's simply because 'scenery' is an uncountable noun, just like 'furniture', 'information' and 'bread'.
