This brooding 2nd-century Roman city gate – blackened by time (hence the name, Latin for ‘black gate’) – is a marvel of engineering since it’s held together by nothing but gravity and iron clamps.
In the 11th century, the structure was turned into a church to honour Simeon, a Greek hermit who spent six years walled up in its east tower. After his death in 1134, he was buried inside the gate and later became a saint.
