While exploring the historic Ano Poli, the Old City or Upper Town, you will stumble upon the old city wall and the Heptapyrgion. It is a Byzantine and Ottoman-era fortress. You can pay to see the renovated interior part, which used to serve as a prison from 1890 to 1990. Enjoy your urban hike up to the monument, check out the panoramic views and sip a frappe in one of the charming cafes in the area. Also known as Edy Kulѐ or Eptapirgio, 'Seven Towers', is a medieval fortress with towers in the northeastern part of Thessaloniki. Despite its name, the fortress has ten towers. The fortress was built in the IX century, and some parts of it were built later. Like the White Tower, it was used as a prison from the late 19th century until 1978.

The former royal palace of King Roger II in the 1100s, Palazzo dei Normanni is one of the most famous sights in Palermo. Dating back to the 9th century, the palace owes its current appearance to the embellishments realised by the Normans: covered in dazzling Byzantine mosaics, the Arab-Norman architecture is a symbol of the political and cultural union operated by the Normans. Be sure to check out the stunning Palatine Chapel.

This 12th century fortress keeps watch over the port and the Old Town of A Coruña. Today it houses a Museo Arqueoloxico e Historico (The Historical and Archaeological Museum) with an array of ancient Egyptian, Roman, Visigoth and contemporary pieces.

Allegedly the best art gallery in Palermo, the Galleria Regionale della Sicilia Palazzo Abatellis exhibits artworks of Sicilian artists from the Middle Ages, artefacts from the Arab period, and paintings from the 17th and 18th centuries. Take your time to admire the stunning Palazzo Abatellis, built in the 15th century in the Gothic-Catalan style.