Quiz: Lands kept apart, or together, by a sliver

1 / 6 |
Clockwise from top left, these are the cities of Auckland, Manila, Seattle, and Madison. What do they have in common in line with this quiz’s theme?

2 / 6 |
Name the narrow waterway that separates Europe from Asia and which has been central to trade and warfare for centuries. Once called the Hellespont, it connects the Sea of Marmara with the Aegean. Xerxes’s army famously crossed it on a pontoon bridge in 480 BC, followed by Alexander the Great in 334 BC.

3 / 6 |
This 77-kilometre-long structure connects the Atlantic and Pacific Oceans via a narrow Central American land bridge, saving ships nearly 13,000 km of travel. Its construction reshaped global shipping routes and required a major effort to conquer both tropical disease and terrain. Name it.

4 / 6 |
This strait is only 3.8 km wide at its narrowest point. It separates a British overseas territory from the Spanish mainland, connects the Atlantic Ocean to the Mediterranean Sea, and is home to a famous rock with mythic associations. Name the strait.

5 / 6 |
This narrow strait links the Crimean Peninsula to the Russian mainland and has been of strategic military interest since ancient times. It is also the site of a modern bridge that’s often been in the news vis-à-vis Russia’s war against Ukraine. Name the straight.

6 / 6 |
Often mistaken for a human-made structure, this natural feature is a slender land connection between two large landmasses, separating the Pacific Ocean from the Arctic ocean. During the Ice Age, it helped humans cross from the upper edges of Asia into North America. Name it.