The modern Slovenian Littoral is only a part of the former Österreichisches Küstenland (Austrian Littoral), as big parts now belong to Italy. The city of Trieste was the only seaport of the otherwise landlocked Austro-Hungarian-Empire. Probably you remember the scene from the movie Sissi where the Austrian Emperor visits his neighbor Venice and is greeted with annoyed silence. In the movie the situation is saved by the daughter, who runs to meet her mother, and the Italians, who love children, start cheering "Viva la mama!". This gives a good idea of the political situation, and as a result Italy fought quite hard for the territories they were convinced belonged rightfully to Italy during World War I. At the end of the war they owned the whole area and some part of Notrjanska. They lost most of it again in World War II and during the creation of Yugoslavia, and while Yugoslavia existed there was a rather uncomfortable border between the two countries. However, modern Slovenia was able to reduce the conflict and today there are almost no conflicts left, both Italy and Slovenia belong to the EU and Schengen.
The geologic situation is quite impressive: the classical karst, the mountain ridge named Kras, belongs to this area. There is an enormous amount of caves, numerous current and historical show caves, and a extraordinary hydrological situation, with karst rivers draining almost 150 m below the surface and reappearing at the coast or underwater in the sea as submarine sweet-water springs.
The current border between Italy and Slowenia north of Trieste is actually the World War I front. The Miren Kras with its numerous caves along the Italian Austrian border, was the place of years of fighting and many thousand dead soldiers. If you ever saw a movie about World War I soldiers sitting in trenches and being shot at, this is here. For a long time the fighting was stalled here, the Isonzo Line or Isonzo Front it was called. The Italians tried to invade the Kras and the Austrians sat on the hills and defended. They built trenches and used the natural caves as bunkers. The caving and building section of the Austro-Hungarian army researched and rearranged many caves on the karst plateaus.
The 100th anniversary of World War I, between 2014 and 2018, made public funding available all over Europe along the front. This Italian-Slovenian borderland is no exception. On both sides numerous caves were reopened, cleaned and preserved. On the Slovenian side the Jamarski klub Temnica (Temnica Caving Club) did the work. They are locals and started with this work decades ago and have already cleaned half a dozen caves quite successfully.
Jama Pečinka (Pečinka Shaft), a World War I military shelter which is now a museum, is a good starting point. The caves Krompirjeva jama, Klobasja jama, Lojzova jama and Ruska jama, which once served as shelters, are also open for visit. However, they are open only at weekends or some only after appointment. We recommend one of the guided walks of the Miren Karst project, you walk about 5 km guided by a caver and see several caves and numerous surface remains. A quite impressive half day experience with optional lunch. As we organized showcaves.com by political borders your will find additional info on the Italian side: Grotta del Monte Ermada