In the Julian Alps north of Trieste, the Trans-Slovenia mountain bike route is 420km long with 14,500m of climbing. The route starts south of VIllach, Austria, and runs down through the Julian Alps to the Adriatic Sea southeast of Trieste.
There are several route options for the TransSlovenia mountain bike route. The western most routing is usually broken into several stages such as Villach to Kranjska Gora, Kranjska Gora to Bovec (50km/1100m), Bovec to Kobarid (40km/1200m), Kobarid to Tolmin (40km/1400m), Tolmin to Solkan (60km/1400m), Solkan to Sezana (70km/1400m), and finally Sezana to Piran (70km/1600m) on the Adriatic Coast. The middle route, which is just east of the western route, is usually broken into several stages such as Villach to Kranjska Gora, Kranjska Gora to Kobarid (75km/2050m), Kobarid to Tolmin (50km/2250m), Tolmin to Vipava (65km/1550m), Vipava to Postojna (48km/1680m), Postojna to Kozina (66km/1900m), and finally Kozina to Piran (85km/1295m) on the Adriatic Coast. Lastly, the east route is an easier version of the middle route that avoids singletrack.
Overall, Trans Slovenia is the 1st most popular mountain bike trail of all 3 mountain biking rides in Slovenia.