Unique in Greece, the Rotunda is a cylindrical building from the early 4th century AD. The mosaics inside are really impressive. The Rotunda is a massive circular structure, built in 306 AD, with a masonry core. Through its long history, it has gone through multiple periods of use and modification as a polytheist temple, a Christian basilica, a Muslim mosque, and a Christian church once again. A minaret is preserved from its use as a mosque, and ancient remains are exposed on its southern side. Some Greek publications claim it is the oldest Christian church in the world. These days, the Rotunda is primarily an archaeological site, where you can see some remaining Christian mosaics and feel the weight of history.

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.

Piloersemaborg, a 17th-century manor in Den Ham, stands as a historical gem just a short drive from Groningen. Surrounded by avenues and canals, this sole surviving manor farm in the Netherlands offers a glimpse into the life of squires with its stately architecture and rural charm. Initially built in 1633 and later restored, Piloersemaborg now hosts a restaurant, blending its rich history with contemporary culinary delights. Sheltered by trees and encompassed by a moat, it presents an idyllic retreat into the past.