The Rhubarb Triangle is an area in Yorkshire famous for its centuries-long cultivation of forced rhubarb. Most people locate it between the towns of Wakefield, Morley and Rothwell, although occasionally Wakefield, Morley and Leeds are alleged to be the Rhubarb Triangle's true vertices.
Forced rhubarb is rhubarb that is grown unseasonably early by artifically raising the temperature. First the farmers start the stalks outside, then, after two years, move them into heated sheds, where they grow in complete darkness. In these sheds the rhubarb grows gradually sweeter and more tender until it is ready to be harvested.
In celebration of its long history of cultivation, the town of Wakefield holds an annual Rhubarb Festival.