Wrexham is not built on a major river, but on a relatively flat plateau between the lower Dee Valley and easternmost mountains of north-east Wales. This position enabled it to grow as a market town, as a crossroads between England and Wales, and later as an industrial hub – due to its rich natural reserves of iron ore and coal. But three small rivers flow through parts of the town: the Clywedog, Gwenfro and Alyn. Wrexham is also famed for the quality of its underground water reserves, which gave rise to its previous dominance as a major brewing centre.