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.
Sigmaringen Castle was first mentioned in the year 1077 in the chronicles of Petershausen monastery. The oldest parts of the castle are concealed beneath the alterations made during the 17th and the 19th centuries. The secret of the earliest settlement built on this defendable rock will never be fully revealed: large-scale excavation work would be necessary, which the extensive land development renders impossible. Judging from the many Roman remains unearthed in the area around Sigmaringen, the 12th century keep known as the 'Roman Tower' could be traced back to a Roman predecessor.
The castle remains that have been preserved (gate, great hall and keep) date back to the Staufer period around 1200. The castle remains were integrated into subsequent buildings. The foundations of the castle buildings are to a large extent identical to the surrounding castle wall.
These remains give us a good idea of how the castle might have looked during the 12th century.