Croatia has border crossings with Slovenia, Hungary, Serbia, Bosnia and Hercegovina, and Montenegro.
Direct bus connections link Croatia to all of its neighbours and to as far afield as Norway. In most cases, passports are collected on the bus and handed over at the border; you usually won't leave the bus unless there's an issue that needs resolving. Useful websites include www.eurolines.com, www.buscroatia.com, www.getbybus.com and www.vollo.net.
Austria Direct connections from Vienna to Zagreb, Varaždin, Osijek and Split.
Bosnia and Hercegovina Direct buses to Sarajevo from most Croatian cities. Good connections between the Dalmatian coast and popular spots such as Mostar and Međugorje.
Germany Direct connections from Berlin and Munich to Varaždin and Zagreb, and from Frankfurt to Split.
Hungary Direct services between Budapest and Split.
Italy Routes include Padua, Venice and Trieste to Rovinj, Pazin and Pula; Trieste to Split, Makarska and Dubrovnik; and Milan to Zagreb.
Montenegro Regular services between Dubrovnik and the Bay of Kotor.
North Macedonia Direct buses from Skopje all the way to Istria.
Serbia Buses from Belgrade to Vukovar, Osijek, Zagreb, Rovinj and Pula.
Slovenia Buses from Ljubljana to Poreč, Zagreb, Split, Makarska and Dubrovnik, and from Maribor to Varaždin.
Switzerland Direct connections between Zürich and Osijek.
Zagreb is Croatia's main train hub but direct international services also head to Osijek, Rijeka and Pula. In most cases, passports are checked on the train. Useful websites include www.raileurope.com and www.eurail.com.
Austria Vienna to Zagreb.
Germany Munich to Zagreb.
Hungary Budapest to Zagreb.
Serbia Belgrade to Zagreb.
Slovenia Ljubljana to Zagreb, Rijeka and Pula, and Maribor to Zagreb.
Switzerland Zürich to Zagreb.