What's more amazing: how much things have changed over the last 1,800 years, a major chunk of the civilizational history of humanity, or how many of this map's divisions are still with us today?

This might be useful in planning your next vacation, although there are some big surprises in the results.

This map is a reminder that the world's divisions and commonalities go much deeper than national borders. It also helps to tell the stories of a few major events that still shape the globe, the echoes of which you can see in almost every map on this page:European colonialism, the Arabic-speaking Islamic conquests of the 7th century, the Russian expansions of the 19th and 20th centuries, and the (still-ongoing!) unifications of India and China.

Here's how they decided which countries are best to born in and what this map tells us about the world.

Read here about how Christianity came to dominate so much of the globe and what that means today. Read below for more on the Islamic world.

People in yellow countries are the least likely to report having emotional experiences of any kind, positive or negative. Purple countries are where people report experiencing the most feelings. If you're surprised to see that the United States is among the world's most emotional countries (but far from No. 1) or want to learn why some regions are so unemotional, you can read all about it here.

I have this one hanging over my desk in part because of its appeal as a historic document (the borders are tellingly rough) but also as a reminder of the colonial legacy in Africa, which European powers divided up a century ago with little respect for how actual Africans wanted to be grouped. Those arbitrary borders are still with us today, in part because African leaders agreed not to dispute them when they won independence. The borders contribute significantly to conflict and unrest on the continent because there are so many diverse communities forced together.

People in blue countries are more likely to say that they would be OK with living next door to someone of a different race. People in red countries are less likely. The mapsuggests some big and potentially surprising lessons for how race is treated around the world. But it's an imperfect (and controversial) metric, so do read these five insights from an ethnic conflict specialist on the map and what it tells us.

This shows the world's most diverse countries, its most homogenous and, if you look closely, a whole lot more.

Red countries are where people feel the most loved; blue countries are where they feel the least loved. Here's the story behind those sadder, bluer spots on the map.

Professor Igor Panarin became a minor celebrity in Russia when he first unveiled his grim prediction for the future of the United States, which was widely covered by Russian state media and treated as credible. Panarin said the United States would break apart under internal strain and form four different countries, with only one wholly independent while the others fell under foreign influence or control. I've included it both for a taste of how the United States is sometimes perceived abroad and to give American readers a sense for what it can feel like to have the outside world get your country so wildly wrong.

People in blue countries are more likely to view the United States favorably; people in red countries are more likely to view it unfavorably. The map has some big implications for America's role in the world.

This map is actually mostly good news for the United States. Here's why.

Sometimes maps can spark geopolitical events rather than just reflecting them, as China did when it issued new passports containing this map. Why the controversy? The areas I've highlighted in red are marked as Chinese on the map but actually are in dispute or are administered by other countries. This did not go over well.

Click here for four big takeaways from this map.

What this has to do with gay rights.

The first thing this map shows you is the remarkable diversity in one of the world's oldest and most storied regions, from Iraq in the West all the way to China in the East and Russia in the North. There are a hundred other stories embedded in here: the expansion of Iran beyond just Persian-speaking peoples, the fracturing of Afghanistan and Pakistan, and the really stunning diversity packed into the Caucasus, which includes the troubled Russian regions of Chechnya and Dagestan.

Read more here about Russia's cigarette problem, which costs the country an estimated $48 billion every year, and about the other smoking trends seen in the map.

This map shows each country's gini coefficient, which measures economic inequality. The red countries are the most unequal under the metric, and the green countries are the closest to nationwide economic equality. More here.

Blue countries are more equal than the U.S., red countries are less equal. This map gives you a sense of just how severe economic inequality is in the United States; much higher than in any other developed country, and most developing countries as well.

A University of Minnesota study recently published in the journal Nature found that a significant share of the world's crop-growing regions are seeing growth stagnate, slow or even collapse. They published three other maps; see the others and why they think it's so important to "sound the alert" here.

A international NGO designed a complex formula to indicate which countries are better or worse for mothers. Click here to see what their formula measures and to read about the study's implications for mothers worldwide.

This map of core al-Qaeda and its affiliates tells the story of its recent decline, but it also reminds us of the group's ability to continue branching out.

It's even more amazing when you see the numbers broken down.

One reason I find this map fascinating is it shows how British colonialism took the English "common law" legal system -- once nearly unique in the world -- and has now spread it across every continent. You can also see that religious law is unique to Islamic countries (although it didn't use to be) and that customary law, once near-global, is now almost extinct.

This helps drive home why Israel is so concerned about Hamas, the Gaza-based Islamist militant group, and in particular about its access to Iranian-made Fajr-5 rockets. Those are the ones that can reach into the light-yellow region.

North Korea makes its missile program sound like a terrifying and immediate threat to the United States, but, as this map demonstrates, that rhetoric far exceeds actual capability.

The United States ranks 34th out of the developed world's 35 countries by child poverty rates, above only Romania. The United States doesn't do much better on overall child well-being.

China's problem with "cancer villages," or communities where cancer rates are spiking, thought to be due to rapidly worsening pollution, have become such a big problem that even Communist Party-run outlet Global Times felt compelled to share this map on Chinese social media.

Europe's economic slump is no secret, but how people within the European Union feel about their big collective experiment can very widely. This map is a pretty telling indication of whom the E.U. has helped, whom it has hurt and who think they shouldn't really count as European (read: the United Kingdom).

There are barely two dozen left, and only 11 of them are really still in charge, but they've all got a story to tell. Read a mini-bio of each one here.

This color-coded map shows the different ethnic groups of Syria, Lebanon, Jordan and Israel. There's an awful lot of history packed into this corner of the world -- and maybe some of the deepest ethnic and religious animosities anywhere in the world.

The Cold War may have ended, but its thousands of nuclear warheads are still around -- and often still divided along the same lines. This map shows in blue the Russian "umbrella states," which are formally under the protection of Russian nuclear weapons, and in orange the "umbrella states" protected by the U.S./NATO. The five other nuclear powers -- Israel, Pakistan, India, China and North Korea -- are in gray.

Click to enlarge. Data source: Gallup (Max Fisher/Washington Post)[/caption]

People in red countries are pessimistic about their country's economy; people in blue countries are more optimistic. With a handful of exceptions (cough cough, China), economists seem to agree.

Each of these red markers cheekily indicates some unusual or unique phenomenon -- for example, Abkhazia, the "barely recognized puppet state" just between Russia and Georgia. (Read more on Abkhazia and other not-yet-real countries here.) My favorite may be the various overseas French territories, such as French Guyana, that are simply and accurately labeled "France." The map was designed by Stanford Professor Martin Lewis; read his full post explaining the map here.

Plenty of godlessness in China, Japan and a few European countries, perhaps unsurprisingly. But there are lot more atheists in places like Saudi Arabia than you might think, despite the fact that it's considered a serious crime.

The first of three maps from a comprehensive study on attitudes and views in the Muslim world (full breakdown of the report here) shows that most Muslims broadly support democracy, with a few telling exceptions.

Significant shares of just about every large Muslim population worry about religious conflict (there is a widespread view in many Muslim-majority countries that the religion is under siege from the outside world). That share is more than half in four countries: Tunisia, Pakistan, Nigeria and Niger.

Red indicates countries where most surveyed Muslims believe that "honor killings" -- the practice of killing someone, typically a member of your own family, for having sex out of wedlock -- are sometimes justified. Blue indicates countries where most surveyed Muslims believe it is never justified.

This NASA moving image, recorded by satellite over a full year as part of their Blue Marble Project, shows the ebb and flow of the seasons and vegetation. Both are absolutely crucial factors in every facet of human existence -- so crucial we barely even think about them. It's also a reminder that the Earth is, for all its political and social and religious divisions, still unified by the natural phenomena that make everything else possible.