Why does Paris look the way it does?

Well, until the year 1853 it was a diseased and overcrowded Medieval city — then the biggest urban renovation in history was announced.

This is the story of how Paris was transformed into the world's most popular city... First: the context.

King Louis-Philippe of France was overthrown in 1848 and Louis-Napoleon, nephew of Napoleon Bonaparte, was elected President of the Second Republic that same year.

Three years later he staged a coup and became Emperor Napoleon III — France's final monarch.

Exactly 113 years ago today an explorer called Hiram Bingham III was led to some mysterious ruins in the mountains of southern Peru.

Those ruins turned out to be Machu Picchu.

This is the story of the last citadel of the Inca Empire... Historians generally agree that there were six "cradles" of human civilisation.

These "cradles" were places where civilisations emerged independently and without external influence.

First in Mesopotamia, modern-day Iraq, and also in Egypt, the Indus Valley, China and Mexico.

It's easy to ignore them, but roofs are often the most interesting part of a building.

Why? Because they have an endless variety.

So here is a very brief introduction to the surprising beauty of roofs... There are exceptions, but pretty much every type of building needs a roof, from the humblest home to the grandest temple.

The very origins of architecture itself lie in the need for shelter — for a roof above our heads.

It gives protection, from the elements or other people.

Angkor Wat in Cambodia is one of the most famous places in the world, and rightly so.

But what is it, who built it, and when?

Well, the first thing to say is that Angkor Wat stands at the heart of a colossal, abandoned city... Angkor is the name of an historic (and ruined) city in northwestern Cambodia.

It was the capital of the Khmer Empire from the 9th to the 13th centuries AD, and in those years it rose to become one of the world's major urban centres.

But Angkor was abandoned in the year 1431.

174 years ago there was a huge storm in northern Scotland, and it uncovered something strange.

From beneath the soil emerged a perfectly preserved village older than the Pyramids, and it even had furniture.

This is the 5,000 year old story of Skara Brae... Orkney is the name of an archipelago just off the coast of northern Scotland.

It was here, in 1850, that a colossal storm partly destroyed a grassy hill by the sea.

When locals investigated they discovered that it had revealed what seemed to be walls made of large stones.

Rembrandt, who lived 400 years ago, is usually called one of the greatest artists who ever lived.

But why? What made him so good?

Strange as it sounds, what made Rembrandt special was the way he painted himself — and how many times he did it... Rembrandt Harmenszoon van Rijn was born in the Netherlands in 1606.

By 18 he was a painter, but unlike others of his generation he refused to study in Italy and remained at home.

At 22 he painted this brooding, supremely confident self-portrait — and a star was born.

The Rosetta Stone was discovered exactly 225 years ago today — inside the wall of an old fortress that was being demolished.

This is the strange story of the stone that brought Ancient Egypt back to life... Why is it called the Rosetta Stone?

Because it was discovered near a town called Rashid in northern Egypt — when the French invaded in the late 18th century they corrupted its name to Rosetta.

Why do the badges of the England and Spain football teams look the way they do?

It's a story that involves the Holy Roman Empire, a purple lion, Hercules, and the possible origins of the dollar sign... When England first played an international match in 1872 — the first international game in history, against Scotland — they simply wore three lions as a crest.

The ten roses were added in 1949, one for each region of the Football Association.

(That first game was a 0-0 draw).

This painting is one of history's most controversial and influential works of art.

It's by James Abbott McNeill Whistler, who painted it all the way back in 1875.

Why was it so controversial? Because it totally redefined the meaning of the word "art"... James Abbott McNeill Whistler, born on this day in 1834, helped change the world of art.

He was an unusual man who essentially created a personality for himself, as though he were a character in a novel.

This portrait by Walter Greaves, from 1869, sums him up well.

A brief guide to Japanese architecture: The words "Japanese architecture" are incredibly broad and could refer to hundreds of different things.

Like Metabolism, an unusual and short-lived style that emerged in the late 1950s, epitomised by the now-demolished Nakagin Capsule Tower:

Edinburgh is often called one of the world's most beautiful cities, but what makes it so special?

Well, Edinburgh is built around an extinct volcano, and so it's a perfect example of how interesting geography leads to interesting architecture... Edinburgh's location is unusual — the city is centred around a castle built on an extinct volcano, to the right of this picture.

During the Ice Age the surrounding softer rock was eroded, leaving a crag with three steep cliff faces and one long, sloping ascent.

The way we organise time is strange.

365 days in a year, 12 months (of 31, 30, 28, or sometimes 29 days), 52 weeks, 7 days in a week, 24 hours in a day, 60 minutes in an hour, and 60 seconds in a minute.

How did this happen?! The story begins with an Ancient Egyptian sundial... The Ancient Egyptians separated day and night into two blocks of time, each with 12 parts — as we can see on their sundials.

Daylight hours were measured with sundials and night hours by the movement of the stars.

Thus the length of those day and night hours were different.

A short introduction to JMW Turner... Joseph Mallord William Turner, the son of a barber, was born in London in 1775.

He made paintings from an early age and his father sold them in his shop.

This boy was clearly destined for greatness and at 14 he joined the Royal Academy of Arts — by 21 he was painting like this:

Neuschwanstein Castle in Germany isn't a real Medieval castle.

It's less than 150 years old and there are even photos of it being built.

But that isn't unusual — because lots of famous old buildings aren't as old as they seem... Neuschwanstein was built by King Ludwig II of Bavaria, an eccentric man obsessed with Medieval romances and myths.

Inspired by the operas of Richard Wagner, he had Neuschwanstein built in the 1870s as a literal fairytale castle where he could live in his own dreamworld.

A short history of tennis... Although there's evidence that a game sort of similar to tennis was played in Ancient Egypt and Greece, the story of modern tennis begins in 11th century France.

What happened? Monks started playing a game in monastery yards where they hit a ball back and forth.

Summer in art:

1. Woman with a Parasol by Claude Monet (1875) 2. Summer by Pieter Brueghel the Younger (1600)

Times change, jobs change, and technologies change... but some things never change.

A wonderful and witty snapshot of ordinary life in the Netherlands as it was 400 years ago.

Why are so many flags red, white, and blue?

It all started 452 years ago in the Netherlands... The study of flags is called vexillology, and it's a surprisingly interesting subject filled with stories both fabulous and bizarre.

Like how every single national flag in the world is rectangular... apart from the flag of Nepal:

Antoni Gaudí was born 172 years ago today.

He's one of the most beloved architects in the world, and that makes sense — his style is utterly unique.

But Gaudí only designed 17 buildings... Antoni Gaudí was born in Catalunya on the 25th June 1852.

He spent eight years training as an architect, and although involved in some projects at university, his first solo commission was designing... lamp posts.

For the Plaça Reial in Barcelona, in 1879:

Famous paintings and their real life locations:

1. The Church at Auvers by Vincent van Gogh (1890) 2. Mont-Saint-Michel by James Webb (1857)

Notice how Webb has made Mont-Saint-Michel more vertical, elongating the buildings and steepening the hill itself.

A common method used by artists to make real places more picturesque.

Cropped images make it impossible to tell how big a work of art really is.

And that's only one of the many ways that photos have totally changed the way we see art... Unless you go to a gallery, the only way to see art is online, on posters, or in books — pictures of the art rather than the art itself.

It's clearly a good thing that, thanks to the internet, art is more accessible than ever.

But it has led to some misleading impressions...

This Ancient Roman temple in Austria is not real.

It's a "fake ruin" built 250 years ago.

But it isn't unusual, because fake ruins are a whole subgenre of architecture — and there are hundreds of them around the world... These "Roman ruins" were designed by an architect called Johann Ferdinand Hetzendorf von Hohenberg under Holy Roman Emperor Joseph II.

They were built in 1778 at Schönbrunn Palace in Vienna, and decorated to look authentic by a team of sculptors.