Editing Umbria (section)

== Geography ==
[[File:Cascata delle Marmore (24).jpg|thumb|250px|left|[[Cascata delle Marmore|Marmore Falls]].]]
[[File:Gole Nera Mole.jpg|thumb|250px|left|Gole del Nera in [[Narni]].]]
Umbria is bordered by [[Tuscany]] to the west and the north, [[Marche]] to the east and [[Lazio]] to the south. Partly hilly and mountainous, and partly flat and fertile owing to the valley of the [[Tiber]], its topography includes part of the central [[Apennine Mountains|Apennines]], with the highest point in the region at [[Monte Vettore]] on the border of Marche, at {{convert|2476|m|0|abbr=off}}; the lowest point is [[Attigliano]], {{convert|96|m|0|abbr=off}}. It is the only Italian region having neither a coastline nor a common border with other countries. The ''[[comune]]'' of Città di Castello has an exclave named ''Monte Ruperto'' within Marche. Contained within Umbria is the hamlet of [[Cospaia]], which was a tiny republic from 1440 to 1826, created by accident.

Umbria is crossed by two valleys: the Umbrian valley ("Valle Umbra"), stretching from Perugia to Spoleto, and the [[Tiber Valley]] ("Val Tiberina"), north and west of the first one, from Città di Castello to the border with Lazio. The Tiber River forms the approximate border with Lazio, although its source is just over the Tuscan border. The Tiber's three principal tributaries flow southward through Umbria. The [[Chiascio]] basin is relatively uninhabited as far as [[Bastia Umbra]]. About {{convert|10|km|0|abbr=off}} farther on, it joins the Tiber at [[Torgiano]]. The [[Topino River|Topino]], cleaving the Apennines with passes that the [[Via Flaminia]] and successor roads follow, makes a sharp turn at [[Foligno]] to flow NW for a few kilometres before joining the Chiascio below [[Bettona]]. The third river is the [[Nera (Italy)|Nera]], flowing into the Tiber further south, at Terni; its valley is called the ''Valnerina''. The upper Nera cuts ravines in the mountains; the lower, in the {{ill|Tiber basin|qid=Q125054480}}, has created a wide floodplain.

In antiquity, the plain was covered by a pair of shallow, interlocking lakes, the Lacus Clitorius and the Lacus Umber. They were drained by the [[ancient Rome|Romans]] over several hundred years. An earthquake in the 4th&nbsp;century and the political collapse of the Roman Empire resulted in the refilling of the basin. It was drained a second time, almost a thousand years later, during a 500-year period: [[Order of Saint Benedict|Benedictine]] monks started the process in the 13th century, and the draining was completed by an engineer from Foligno in the 18th century.{{Citation needed|date=July 2023}}

The eastern part of the region, being crossed by many [[Fault (geology)|faults]], has been often hit by earthquakes: the last ones have been [[1997 Umbria and Marche earthquake|that of 1997]] (which hit [[Nocera Umbra]], [[Gualdo Tadino]], Assisi and Foligno) and those of [[August 2016 Central Italy earthquake|August]] and [[October 2016 Central Italy earthquakes|October 2016]] (which struck [[Norcia]] and the Valnerina).<ref>{{cite news|last1=Casalini|first1=Simona|title=Terremoto in Centro Italia|url=http://www.repubblica.it/cronaca/2016/10/30/news/terremoto_rieti-150898762/?ref=HREA-1|access-date=30 October 2016|work=Repubblica|date=30 October 2016|language=it}}</ref>

In literature, Umbria is referred to as ''Il cuore verde d'Italia'' or ''The green heart of Italy''. The phrase is taken from a poem by [[Giosuè Carducci]], the subject of which is the source of the [[Clitunno River]] in Umbria.