Acropolis, Athens

The Eastern Mediterranean is an open-air museum showcasing the marvels of the ancient world. With ruins and historical sites dating back thousands of years, there are few regions that can rival its cultural riches. Some of the world's earliest civilizations flourished around the Mediterranean, which was called Mare Nostrum (meaning "Our Sea") at the time of Roman Empire.

Today, Eastern Mediterranean cruises typically take in Cyprus, Greece, Turkey, Croatia, Italy, Tunisia and Israel. Take a step back in time with our choice of ten top sights.

Athens (Piraeus): Acropolis

The Acropolis, overlooking Athens, is among the most recognizable remnants of ancient Greece and widely regarded as the most important ancient monument in the western world. Meaning "high city", the Acropolis was first inhabited in Neolithic times, and people lived there until 510 BC when it was declared that it should be the province of the gods. The site includes the Parthenon temple, built for the goddess Athena. Rubbing shoulders with these ancient wonders is the magnificent Acropolis Museum, which opened at the foot of the Acropolis in 2009 and is ten times larger than the previous museum of the same name. Many of the priceless artefacts now displayed had never been on public show before due to lack of space. If you're not joining a guided tour, a combined ticket provides entry to the Acropolis and museum.

Tip: Wear flat, rubber-soled, closed-toe shoes or sneakers, as the marble and stone paths can be slippery and uneven.

Venice: St Mark's Cathedral

This fabled watery city, built on islands and criss-crossed by bridges, makes you feel as if you've stepped into an oil painting. St Mark's -- the grandest square in Venice -- is dominated by the cathedral of the same name. One of the finest examples of Byzantine architecture in the world, it incorporates a variety of art and architectural details from antiquity to the Middle Ages. These include some of the oldest known exterior mosaics, dating back to the 13th century; a fabulous gold interior symbolizing the divine light of God; and an intricately patterned mosaic and marble floor. In total, there are more than 85,000 square feet of mosaic in St Mark's -- enough to cover over 1.5 American football fields.

Tip: There's always a line for tickets (on average 45 minutes, and longer in the busy summer months) so book an organized excursion to avoid waiting.

Dubrovnik: City Walls

Known as the Pearl of the Adriatic, Dubrovnik is one of the most impressive and complete walled cities in the world. The intact city walls date back to the 13th century and run uninterrupted for more than one mile, completely encircling the UNESCO-listed old town. You'll get the best view of the city's distinctive patchwork of red roofs by walking around the battlements. Nearly 20 feet thick in places, the walls were built to protect the city from attack and are dotted with lookout towers. Guided tours are available, but it is easy to visit on your own if you prefer to go at your own pace; ; it takes around two hours to complete the circuit. It's worth getting there as early as possible to avoid crowds and the midday heat.

Tip: The stone steps leading to the walls are steep and the walk is tiring in hot weather. For an easier option with equally panoramic views of the old town and harbor, take the cable car to the top of Srd Hill.

Ephesus, Turkey

Izmir and Kusadasi: Ephesus

Ephesus is best conserved classical city in the Eastern Mediterranean, and the vast size and scale provides a real flavor what day-to-day life was like in Roman times. Due to its strategic location on a trading route, it grew into the second largest city in the Roman Empire and most important commercial center in the region. The Temple of Artemis, visited by Alexander the Great during its construction in 334 BC, was one of the Seven Wonders of the Ancient World. Although little remains of that temple, Ephesus contains many remarkable ruins, including a large theater, private houses, mosaics, statues and frescoes. Shore excursions are offered from the Turkish ports of Izmir and Kusadasi, and independent travelers can arrange for taxis to drop them off at one end of the city and collect them at the other.

Tip: Ephesus gets extremely hot in the summer so take a hat, water and sunscreen. Also make sure you have some small change as you have to pay to use the public restrooms.

Jerusalem (Ashdod) and Haifa: Western Wall

With more than 3,000 years of history, Israel's capital, largest city and spiritual centre of the Jewish, Muslim and Christian religions is an incredible destination. Accessible from Haifa and Ashdod, the centerpiece of Jerusalem is the Western Wall; often called the Wailing Wall, it is all that remains of the Second Temple, the most important religious shrine for Jewish people. The area in front is an open-air synagogue with separate areas for men and women, and people come to leave prayers, written on pieces of paper and pushed into the wall. Above ground, the wall is 200 feet long, but excavations have revealed that the majority of its original length -- more than 1,500 feet -- is hidden underground. These foundations, and the remains of ancient streets, can be seen on a fascinating guided tour through the Western Wall tunnels.

Tip: Women must cover their shoulders and knees as a mark of respect. Anyone wearing a sleeveless top, shorts or short dress will be provided with a shawl from a communal basket to use as a cover-up.

Istanbul: Blue Mosque

Istanbul is the former capital of three successive empires: Roman, Byzantine and Ottoman. The city's landmark symbol is the Blue Mosque (called Sultanahmet Camii in Turkish), which was built between 1609 and 1616 during the rule of Ahmed I, the sultan of the Ottoman Empire. It is one of two mosques in Turkey, and only a few in the world, to have six minarets. It is known as the Blue Mosque due to the 21,000-plus handmade tiles that color the vast interior, incorporating 50 different designs. Before entering, visitors must take off their shoes and carry them in the plastic bags provided; women must also don a head covering, also available for free at the entrance.

Tip: A working place of worship, the mosque is closed five times daily, for around 90 minutes, during the call to prayer. The one most likely to affect visitors is midday. Also, on Fridays -- the most holy day of the week for Muslims -- it is closed until 2:30 p.m.

Valetta, Malta

Malta (Valetta): St John's Co-Cathedral

St. Paul, who was shipwrecked en route to Rome in AD 60, brought Christianity to Malta. Religion has played an important role in Maltese history and this is reflected in the 365 churches and chapels that dot the islands. A highlight is St John's Co-Cathedral in Valetta, the capital city, where the rather plain facade makes way for a lavish and ornate interior. The structure was built between 1573 and 1577 by the Knights of the Order of St. John of Jerusalem, who ruled Malta for more than 200 years. The knights donated gifts of high artistic value to enrich the cathedral, and the collection includes two of Italian artist Caravaggio's most impressive works: The Beheading of St. John the Baptist and St. Jerome Writing.

Tip: Stiletto heels and narrow-heeled shoes are not permitted on the inlaid marble floor. Slippers can be purchased at the door for less than two euros per pair.

Tunis (La Goulette): Carthage

The most famous settlers to make their mark on Tunisian soil were the Phoenicians, who arrived around 1100 BC and went on to found their mighty capital Carthage some 200 years later. It was the birthplace of the legendary general Hannibal, who led the first of three wars against Rome, the city's arch rival. A short distance from Tunis, Carthage's three-tier history can be seen through Phoenician, Roman and Byzantine remains spread over a wide area. Don't miss the Antonine Baths, the third largest such complex in the world. The equivalent of a modern-day spa, this was the preferred place for bathing, exercising, reading, and socializing. Also, be sure to take in spectacular views of the whole of Carthage from the top of Byrsa Hill.

Tip: Visit the adjoining Carthage Museum to get a complete picture of the ancient city. It contains artifacts and remains unearthed during the various periods, and a model of how Carthage would have looked at its peak.

Crete (Heraklion): Knossos

Considered by many historians to be Europe's oldest city, Knossos is the largest Bronze Age archaeological site on the Greek island of Crete. Although it's easy to explore the ruins on your own, it pays to have a guide who will bring the enthralling stories of Knossos to life. The home of kings, queens and an army of servants, the 1,000 rooms of the original palace were spread over four floors and connected by a labyrinth of staircases, corridors and secret tunnels. Knossos was used as a location in the 2014 movie "The Two Faces of January" and it's fun to try and spot the areas that were used.

Tip: Follow up a visit with a trip to Heraklion Archaeological Museum, three miles away, which houses the palace's treasures, including art, jewelry and pottery.

Paphos, Cyprus

Paphos (Limassol): Tomb of the Kings

Behind the modern town of Limassol lies an ancient city that was the former capital of Cyprus. The sightseeing highlight is the Tomb of Kings, dating from 4 BC. The name is slightly misleading as high dignitaries and officials, rather than kings, were buried here, but the underground tombs are unquestionably impressive and worthy of their royal tag. Carved out of solid rock, they were created to resemble the houses of the living in the afterlife, and many feature stairs leading down to shady courtyards lined with imposing columns and the remains of frescoed walls.

Tip: Paphos is also home to the house of Dionysos, a villa containing some of the best preserved mosaics in the Mediterranean area.