Thessaloniki is the second largest city in Greece and capital of the region of Central Macedonia, in the northeast of the country. Founded over 2,000 years ago, this city's history gives it an incredible cultural heritage, and a wide variety of sights and monuments, from different cultures, such as the Macedonian, Roman, Byzantine and Ottoman periods. The city's main attraction point is, without doubt, the large number of early-Middle Ages churches spread within the city borders: these have, in fact, been inscribed as UNESCO Wolrd Heritage Sites some 25 years ago. The most important ones are the St Sophia and St Demetrios churches, but you shouldn't miss the other 13 monuments that make up with World Heritage Site. The Byzantine walls are a sight not be missed, as is the White Tower (symbol of the city), which is the last remaining from these 500-year old fortifications. The city's airport is among the busiest in the country, and has many domestic and international routes operating from it, connecting the city to destinations such as Heraklion, Athens, Frankfurt, Moscow, London, Istanbul and Rome. If you're searching for a cheap flight (from London or anywhere else), use our online comparison tool to buy the flight option that suits you best.