Coastal Montenegro is the Adriatic's quietly spectacular underdog, a short stretch of shoreline that packs in a fjord-like bay, walled medieval towns, and beaches at a fraction of the cost of its Croatian neighbors. The showpiece is the Bay of Kotor, where mountains drop straight into still water and the UNESCO-listed town of Kotor coils its cobbled lanes behind old walls, complete with a fortress climb for the views and a famous population of friendly cats that delight younger children more than any monument. Nearby Perast and Tivat add gentle promenades, waterside cafés, and boat trips out to the little island churches in the bay.

For straightforward beach days, the Budva Riviera lines up sandy and pebbled stretches like Bečići and Petrovac, with calm, shallow water that suits young swimmers and resorts with pools and kids' clubs close behind. The region stays interesting on either side: a photo stop at the islet of Sveti Stefan, kayaking and biking around the Luštica Peninsula, and a short drive inland to Lake Skadar for birdlife and boat trips. The accommodation runs from boutique hotels and modern resorts to self-catering apartments and coastal villas, most pitched at families and at prices that still feel like a discovery. Montenegro's coast offers the medieval-meets-Mediterranean appeal of the wider Adriatic, with smaller crowds and a gentler bill, which is exactly why families keep finding it before everyone else does.