Khan al-Umdan ('Caravanserai of the Pillars') is the largest and best preserved caravanserai (roadside inn where travelers could rest and recover from the day's journey) in Israel. Located in the Old City of Acre, it is one of the prominent projects constructed during the rule of Ahmed Jezzar Pasha in Galilee, under the Ottoman era.
Being one of four Khans in Acre, Khan al-Umdan was built in 1784 on the place of the Royal Customs house of the Kingdom of Jerusalem. It incorporates forty columns made of granite that were taken from Caesarea, Atlit and the ruins of Crusader monuments in Acre itself.
Due to its proximity to the port, Khan al-Umdan has throughout its history been an important trading spot. Merchants arriving at Acre used the khan as a warehouse while the second floor functioned as a hostel. Camel caravans once brought produce and grain from Galilean villages to the city's markets and port.
The khan later gained importance to the Baháʼí Faith (as the Khán-i-'Avámid) as it was the site where Baha'ullah used to receive guests, and later the site for a Baháʼí school.
In 1906 a clock tower was added adjacent to the main entrance to the khan to commemorate the silver jubilee of the rule of Ottoman sultan Abd al-Hamid II. It is similar to the Jaffa Clock Tower, a building dedicated to the same purpose, along with five more towers in Ottoman Palestine (in Jerusalem, Haifa, Safed, Nablus, and possibly Nazareth) and over a hundred across the entire empire.
In 2001 Khan al-Umdan, together with the rest of Acre's old city, was designated as a world heritage site. Nowadays, the khan is a major tourist attraction open all hours of the day and used as an open-air stage during festivals in the city, such as the theater festival of Acre during the month of October.
The Church of St Donatus name refers to Donatus of Zadar, who began construction on this church in the 9th century and ended it on the northeastern part of the Roman forum. It is the largest Pre-Romanesque building in Croatia.
The beginning of the building of the church was placed to the second half of the 8th century, and it is supposed to have been completed in the 9th century. The Zadar bishop and diplomat Donat (8th and 9th centuries) is credited with the building of the church. He led the representations of the Dalmatian cities to Constantinople and Charles the Great, which is why this church bears slight resemblance to Charlemagne's court chapels, especially the one in Aachen, and also to the Basilica of San Vitale in Ravenna. It belongs to the Pre-Romanesque architectural period.
The circular church, formerly domed, is 27 m high and is characterised by simplicity and technical primitivism.