The Lady From The Sea by Henrik Ibsen.
I'm going through a bit of an Ibsen phase at present and the latest play I've read is his 1888 play The Lady from the Sea (Fruen fra havet). It reminded me a little of The Doll's House, Ibsen's play from nine years earlier and in fact it was began not long after the play was first produced, but several other plays, Ghosts, An Enemy of the People, The Wild Duck, and Rosmersholm came in between.
'The Lady from the Sea' is Ellida Wangel, the second wife of Doctor Wangel. Ellida is much younger than the doctor and had grown up by the sea in West Norway as the daughter of a lighthouse keeper (the sea is a constant presence in the play). Now married and having recently lost a son, the doctor fears for her health and asks Arnholm, a tutor, to stay with them hoping to somehow help Ellida, however he focuses his attention on Wangel's daughter from a previous marriage, Bolette.
The death of Ellida's son places a great strain on her marriage, but one day a seaman returns: we learn Ellida was once engaged to him but he left having murdered his captain and he has returned to reclaim her. Now she must choose between him and Wangel.
The play is largely, I'd say, about freedom within marriage as well as a kind of self-realisation, but oddly enough for Ibsen, and in contrast with Doll's House this isn't a play laden with doom: this self-knowledge was in fact enough to resist any doubt or temptation and avoid any tragedy; in fact it brought some happiness. It's a great play, one of the best I've read in quite a while.