Because they were built in winter gardens, such as are found in major botanical gardens elsewhere , consisting of plants that flower or have attractive berries or foliage then. In the nineteenth century resorts such as Blackpool tried to attract business outside the traditional season of Summer.One problem was that the resort's gardens, a feature of that season were bare and depressing to see. So they set about establishing public gardens that were attractive from late Autumn, through the winter months. These would be planted with permanent plantings and were usually well away from the bare Summer beds and the exposed sea front. On Britain's west coast, affected by the warm gulf stream, these could include quite tender plants, such as wintersweet, native to mild climates . To go in them they built halls for use in concerts and other entertainments. These were simply named after their location.