The Murge is an area rich in karst formations, which lies mainly in the central part of Puglia and includes the provinces of Bari, Barletta-Andria-Trani, Taranto and Brindisi. The Murge area can be subdivided into the coastal Murgia, the Terra delle Gravine, the Itria Valley, the Murge of Taranto and the Murge of Salento. The Murge are rich in underground waterways, which offer a rich, deep aquifer and numerous small surface aquifers used to irrigate the fields. The Alta Murgia National Park, a recently established country park, is well worth a visit.