Whitby is a seaside town, port and civil parish in North Yorkshire, England. It is on the Yorkshire Coast at the mouth of the River Esk and has a maritime, mineral and tourist economy. From the Middle Ages, Whitby had significant herring and whaling fleets, and was where Captain Cook learned seamanship. He first explored the southern ocean in HMS Endeavour, built there. Alum was mined locally, and Whitby jet jewellery was fashionable during the 19th century.