Montenegro is small, and that is its strength. The Bay of Kotor winds inland between steep mountains like a fjord, with Venetian towns along its shore. An hour or two inland, the Durmitor massif has glacial lakes, pine forest and the Tara Canyon, more than a kilometre deep in places. Lake Skadar, on the Albanian border, is a wetland of water lilies, pelicans and wine villages.
We base most trips on the bay, in Perast or on the quieter Luštica peninsula, and add the mountains for two or three nights. It pairs naturally with Dubrovnik, which is close to the border and has more flights.
The honest caveats are cruise ships and roads. Kotor old town fills when large ships are in, so we plan visits for early morning or evening. Mountain roads are narrow and slow, and the coast around Budva is built up and busy in July and August. June and September are the months to choose.