The Alpe Adria Trail is a recently developed long-distance hiking trail through Austria, Slovenia, and Italy. The project connects existing paths into a single well-documented trail linking the Carinthian Alps with the Adriatic sea via 43 stages and 750 kilometres. Although it passes between high mountains there are no technical Alpine sections and it is described as an "easy to moderate" trail, with many stages suitable for families.
Travelling from north to south, the trail first enters Slovenia via the ridge of the Karavanke Mountains. A long Slovenian section leads from Kranjska Gora across the Vršič Pass to Trenta, and then follows the beautiful Soča Valley downstream. The towns of Bovec, Kobarid, and Tolmin are visited along the way. The trail then crosses the border into Italy, but this is only a temporary goodbye to Slovenia. Further border crossings come later in the journey, with two further Slovenian sections taking the walker through vineyards, orchards, and karst landscapes. The path crosses into Italy one last time to reach the Adriatic at Muggia just outside Trieste.
Comprehensive information about the trail is available online at the Alpe Adria Trail Portal. If you'd prefer to have everything you need to know collected into a convenient book, Bradt Guides have recently published a guidebook dedicated to the trail. The guide is by Rudolf Abraham who has written extensively about hiking in this part of Europe.