Trsteno Arboretum

Trsteno's arboretum was started by the Gučetić-Gozze family, Ragusan nobility who used their trading ships to bring back seeds and saplings from wherever their captains happened to dock. It was already established by 1492, the same year the family built the aqueduct that still irrigates parts of the grounds today — a roughly 70-meter channel rising into a 15-meter arched span carried on four stone arches. It's a working piece of 15th-century engineering, not a restored replica, which is part of why the site matters beyond its plant collection. A decade later, in 1502, the family laid out a formal Renaissance garden around their summer house, generally credited as the oldest of its kind in Croatia.

The arboretum's best-known residents are two Oriental plane trees standing in the old market square, said to be planted more than 500 years ago. Trunk measurements vary depending on who's doing the measuring, but they're consistently described as among the largest of their species anywhere in Europe — one was even put forward as a finalist for European Tree of the Year in 2018 on the strength of its size alone. Between the aqueduct, the Renaissance layout, and trees that predate the garden's most famous visitors by centuries, Trsteno holds up as one of the older continuously maintained gardens on the Adriatic. It's an easy stop to fold into a half-day itinerary, and the arboretum sits right on the coast road a short hop north of the city, which is why Trsteno is worth a visit if you're chartering a gulet from Dubrovnik.