This is Grauman's Egyptian Theatre in Hollywood, built in the 1920s.
Why so grand? Because Hollywood was making 800 films per year and 75% of the American population went to the movies weekly.
What were they watching? Well, 1920s cinema was much stranger than you realise...
Movies had been around since the late 1880s, first as short reels and then as increasingly impressive feature films in the 1910s.
Like Cabiria, an Italian film from 1914, which is sometimes called the first historical epic, with thousands of extras and colossal sets.
But Europe was devastated by WWI and film production essentially ceased.
That gave America a chance to catch up.
By the close of the 1920s about 800 films were being produced every year in Hollywood and weekly cinema attendance was 90 million — American movies were on top.
Four young painters at the French Academy of Fine Arts — Claude Monet, Pierre-Auguste Renoir, Alfred Sisley, and Frédéric Bazille — realise they have something in common.
See, Academic painting took place in studios, with models, much like this:
To these four artists the Academic way seemed artificial, what with its carefully orchestrated lighting.
They also thought it was lifeless, given how it imitated the Renaissance.
And they believed art could be about more than the usual themes of Biblical or Classical history.
This is Borgund Church in Norway, made entirely out of wood and built over 800 years ago.
It is a "stave church", an incredibly unusual type of Medieval building.
What makes them so special? Well, there are only 30 original stave churches in the world...
Norway officially adopted Christianity in the 11th century.
And they started building churches, entirely of wood, often on sites once used for pagan worship.
This boom in church construction continued for three hundred years and culminated in wonders like Heddal Stave Church.
More than 1,000 stave churches were built in Norway alone, with others in Denmark, Sweden, and Britain.
Though some stone churches were built, it was simply the practice in Medieval Norway to make them with wood, seemingly more so than anywhere else in northern Europe.
It sounds like a boring topic, but air conditioning is more important than you realise.
First: there are 2 billion air con units in the world and they account for 10% of all electricity we use.
Second: it has revolutionised architecture and totally reshaped global politics...
In 1901 a New York publishing company had a problem: inconsistent humidity in their factory made it difficult to print in colour.
An engineer called Willis Carrier solved this problem for them by inventing a machine which regulated both humidity and temperature.
Carrier realised the broader potential of his invention and founded a company to mass-produce these climate control machines for domestic and commercial use.
So begins the first part of this story — how air conditioning changed the way our world both looks and works.