The world's 'oldest' mega-city with 19C in November and £15 flights from the UK

The world's population is growing rapidly and is expected to keep rising until around the year 2100, when it's likely to peak. As this happens, more and more places are turning into mega-cities where millions of people live. The term "mega-city" is a modern one, so it's hard to say for sure which city was the first.

But many believe that one ancient capital tops the list, and for good reason. That place would be Athens, the capital of Greece, which is often described as the world's oldest mega-city. It has a recorded history going back more than 3,400 years and was once the centre of philosophy, democracy and art.

Today, Athens is a modern and massive metropolis. According to World Population Review, the city's 2025 population is estimated at 3,155,320, more than double what it was in 1950.

As the birthplace of Western civilisation, Athens is full of historic landmarks. Visitors can climb the Acropolis to see the Parthenon, explore the ancient Agora where democracy was born, and walk among the ruins of the Temple of Olympian Zeus.

But the city also has a modern side. There's a growing contemporary art scene, with galleries like The Breeder and the National Museum of Contemporary Art.

Some other places worth seeing include the Church of Agios Dimitrios Loumbardiaris, the Acropolis Museum, and the ancient Kerameikos cemetery.

Many of the city's original sculptures and treasures are now safely kept indoors, away from the elements.

For anyone planning a trip, November is a good time to go. According to Thomas Cook, the average high temperature is 19C, and it usually stays around 15C during the day.

Nights are cooler, with temperatures dropping to around 10C or 11C. There are four to five hours of sunshine each day, and the sun sets after 5pm.

While November is in the rainy season, showers are light and often pass quickly. Sea temperatures hover around 20C, though it might not be quite warm enough for beach days.

And for those looking to visit, getting there doesn't have to break the bank.

At the time of writing, Ryanair offers one-way flights from London Stansted to Athens for as little as £15 throughout November.

Many other dates show fares under £20, making it one of the most affordable city breaks in Europe this autumn.