This is the place Vincent tells Mary they can run off to after he talks of wanting to leave his wife. He says to her, "'Do you know Cattaro?'... taking her thin fingers and entwining them with his. 'Cattaro, that little place tucked under the mountains, on the Dalmatian coast?'" (23). 

"She had left all that behind her in that little room in Bulstrode Street, where sat the one man in the world that she cared for—the one man, now, who cared for her. There was no one else; there never could be anyone else." (ch 24)