Human settlement in the Ligurian Prealps is very ancient and left significant traces in various places,[4] also thanks to a number of natural caves which eased the conservation of prehistoric remains and artifacts.[5] The area was involved in the Italian campaigns of Napoleone Bonaparte[6] and several fortresses were built on the chain summit and mountain passes. Before the Industrial Revolution and the spreading of motorized traffic the area was characterized by the presence of small rural settlements alongside permanently inhabited villages.[7] Around the end of the 19th century these mountains, like many others in the Italian peninsula, appeared quite barren due to extensive deforestation.[8] Ligurian Prealps had an important role during the Italian resistance movement as refuge and battleground for many partisan units. The Ligurian partisans' deeds on the Prealps were narrated, among others, by Italo Calvino in some of his masterworks.[9] During the post-war period, like in other low-altitude mountain zones of Italy, Ligurian Prealps suffered depopulation[10] and woodland spread in many former cultivated areas which had been abandoned. This increase in woodland is seen as one of the main reasons of the diffusion of wolves in the Ligurian Prealps starting from their refuge areas in the Central Apennine. This later made it possible for the species to recolonize the entire Alpine chain.[11]
Rotating clockwards, the limits of the Ligurian Prealps are: Colle di Nava (which divides them from the Alpi del Marguareis, the other subsection of the Ligurian Alps), river Tanaro, Cevetta stream, Colle di Cadibona (which divides them from the Apennine Mountains), Lavanestro stream, Savona, Ligurian Sea, Albenga, Arroscia Valley, colle di Nava. The W border of the chain is the Colle di Nava not just according to the SOIUSA, but also for the CAI, as stated in its volume Alpi Liguri (Guida dei Monti d'Italia, 1981).[1]
The specificities of the Prealpi Liguri amidst the Alpine chain, recognized in 2005 by the SOIUSA which considers them as a self-standing subsection, during the first half of the 20th century have been backed by the ligurian alpinist Jacques Guiglia[15] Ligurian Prealps are classified into one Alpine supergroup, three groups and nine sub-groups as it follows:[16]
Catena Settepani-Carmo-Armetta (A)
Gruppo del Monte Settepani (A.1)
Costiera Bric Quoggia-Monte Alto or Gruppo del Monte Settepani stricto sensu (A.1.a)
Costiera del Monte Settepani or Displuvio Bormida di Pállare – Bormida di Millesimo (A.1.b)
Costiera Bric dei Pinei-Rocca Roluta or Displuvio Bormida di Pállare – Bormida di Mállare (A.1.c)
Costiera del Bric Gettina or Displuvio Porra – Marémola (A.1.d)
Gruppo del Monte Carmo (A.2)
Costiera del Monte Carmo or Gruppo del Monte Carmo stricto sensu (A.2.a)
Dorsale Spinarda-Sotta or Displuvio Tanaro – Bormida di Millesimo (A.2.b)
Gruppo Galero-Armetta (A.3)
Costiera Galero-Armetta or Gruppo del Monte Galero e del Monte Armetta stricto sensu (A.3.a)
Dorsale del Pizzo Castellino or Displuvio Neva – Pennavaira (A.3.b)
Dorsale della Rocca delle Penne or Displuvio Pennavaira – Arroscia (A.3.c)
The colle del Melogno takes apart Gruppo del Monte Settepani and Gruppo del Monte Carmo, while the colle San Bernardo divides the Gruppo del Monte Carmo from the Gruppo Galero-Armetta, the latter being the highest area of the mountain chain.[17]
On the Ligurian Prealps have been established some Natura 2000SCIs; among them can be remembered Monte Carmo – Monte Settepani (code:IT1323112), Monte Galero (code:IT1323920), Monte Ravinet – Rocca Barbena (code:IT1324011), Monte Spinarda – Rio Nero (code: IT1323014), Bric Zerbi (code:IT1323021), Castell'Ermo – Peso Grande (code:IT1324818) and Ronco di Maglio (code: IT1322216).[18]
^In brackets are showed SOIUSA codes of the supergroup, groups and subgroups; in italic the names of the SOIUSA subgroups according to CAI volume Alpi Liguri (series Guida dei Monti d'Italia), which are reported in the SOIUSA Atlas as synonims.