From Austrians to Nazis to Soviets, this historic Budapest fortress has a history as complex as the city itself.

What might be the oldest living tree in London has survived fires, bombings, and estate agents.

This tree was grafted from the actual tree that led Isaac Newton to ponder the theory of gravity.

One of several Lilliputian portals that are ready to transport passengers to other dimensions, if they can find them.

Rebuilt remains of a temple to Roman god Mithras.

London's amazing modernist public square that never was.

The last four extravagant street signs of London's historic banking street.

The site of London's first coffee house has been serving refreshments of one kind or another for 360 years.

A friendly pub with a sordid past in cock fighting.

The London statue that imitates passersby.

A collection of machines designed to break things for science.

A kaleidoscopic warehouse-maze of handmade neon signs.

One of the few remaining casualties of the London Blitz, this destroyed church has become an enchanting public garden.

This imprint of an old computer keyboard has a unique backstory.

Man-made cave with enigmatic carvings, some say made by the Knights Templar themselves.

The graveyard with the highest IQ in Britain.

A complicated contraption for telling time by the moon.

A monument to one of the most famous modernist Chinese poems and its poet.

A hunched figure depicted on the signs honors a local gentleman who died on an Antarctic expedition.

Mary Kelly was last seen here before she was murdered by Jack the Ripper.

The oldest inn in England served brew to the crusaders.

A glorious pub known for a spiteful printing feud and its famous typeface lost—then found—at the bottom of the Thames.

When the plague struck York, this stone was used to leave supplies for the sick.

This memorial to World War II's fallen airmen shows us the movements of the stars that once guided them.