Bradford sits at the edge of some of the most rewarding countryside in northern England. Haworth, eight miles west, is the Brontë village — the parsonage where the sisters wrote, the long single-street village, and the moorland walks above the river that inspired Wuthering Heights. The Keighley and Worth Valley Steam Railway runs vintage trains between Keighley and Oxenhope through Haworth, and is itself a worthwhile half day.
The Yorkshire Dales National Park opens up north of Skipton, half an hour by train. Saltaire (technically part of Bradford metropolitan but worth thinking of as a day trip) deserves a full half day for Salts Mill and the surrounding model village. Leeds — fifteen minutes east by train — gives access to a much bigger arts and shopping circuit.