Zadar

Zadar is the oldest continuously inhabited city in Croatia. The city proper covers 25 km2 (9.7 sq mi) with a population of 75,082, making it the fifth-largest city in the nation. Zadar has a borderline humid subtropical and Mediterranean climate.
Most important landmarks of Zadar are:
Church of St. Donatus – a monumental round building from the 9th century in pre-Romanesque style, traditionally but erroneously said to have been erected on the site of a temple of Juno.
Roman Forum – the largest on the eastern side of the Adriatic, founded by the first Roman Emperor Augustus, as shown by two stone inscriptions about its completion dating from the 3rd century.
And much newer – The Sea organ. An architectural sound art object and an experimental musical instrument, which plays music by way of sea waves and tubes located underneath a set of large marble steps.