What is the name of an alley which is not open from the other side? I guess something like one-way or a closed alley should be used.
A dead end would almost certainly not be one-way
See also Cul-de-sac - Wikipedia, the free encyclopedia
In AmE you could hear 'dead end' for alleys, streets, etc., and 'blind alley' would also be heard.
Thank you for your consideration.