The publisher British Crime Library Classics reprints a lot of classic and Golden Age mysteries. They publish both novels and anthologies, including themed anthologies such as winter mysteries, country house mysteries, etc. They also have some locked room mysteries, including some by John Dickson Carr.
Seeing their locked room anthologies made me wonder about what the best classic
locked room mysteries might be.
One of the first I read was "The Problem of Cell 13" by Jacques Futrelle (in a Scholastic reprint edition). And of course, there are "Murder on the Orient Express" and "And Then There Were None," among other Christies...