Tvrdalj Castle was the summer residence of Petar Hektorović, the Croatian poet (1487–1572). During the 16th century, the island of Hvar came under attack from the Ottoman Turks. Hektorović, one of the local nobles, undertook to fortify his house so that it could act as shelter for the local citizens.
Tvrdalj is a well-preserved Renaissance building, with a long closed facade on the seaward side, to protect it from attack. The interior courtyard contains a sea-water fishpool, enclosed by a vaulted and arcaded terrace. Next to it is a tower with a dovecote. The living quarters, together with the servant quarters, and several wells, are arranged around the pool. Behind the main buildings is a walled garden where Hektorović cultivated herbs and medicinal plants.
A series of inscriptions are set into walls of the mansion in Latin and Croatian. Those in Croatian are considered to be some of the oldest extant.
In 1571 Stari Grad was again attacked and Tvrdalj was set on fire by the Turks. A year later, Petar Hektorovic died and the damaged Tvrdalj was divided between his relatives. Following provisions in his will, there were gradual improvements made. However, in 1834 the Venetian laws lapsed and Tvrdalj experienced massive construction works: the south wall of the complex was removed, vaults constructed around the pool, a second floor added on either side of the tower, and new two-storey houses were built. The bay in front of Tvrdalj was filled in as part of the harbour improvements. In the 20th century, further major changes were experienced in 1901 when the eastern wall was demolished and houses built over the vault and cistern which is still part of the Tvrdalj entrance.
References:Ehrenbreitstein Fortress was built as the backbone of the regional fortification system, Festung Koblenz, by Prussia between 1817 and 1832 and guarded the middle Rhine region, an area that had been invaded by French troops repeatedly before. The fortress was never attacked.
Early fortifications at the site can be dated back to about 1000 BC. At about AD 1000 Ehrenbert erected a castle. The Archbishops of Trier expanded it with a supporting castle Burg Helferstein and guarded the Holy Tunic in it from 1657 to 1794. Successive Archbishops used the castle's strategic importance to barter between contending powers; thus in 1672 at the outset of war between France and Germany the Archbishop refused requests both from the envoys of Louis XIV and from Brandenburg's Ambassador, Christoph Caspar von Blumenthal, to permit the passage of troops across the Rhine.