Every city has a surface story and a basement story, and the basement story is almost always better. Here are 10 places where the ground floor is just the cover page.
The Paris Catacombs hold the remains of roughly six million people — about three times the city's living population.
Starting in 1786, Paris emptied its overflowing cemeteries into old limestone quarry tunnels, and the network under the city runs close to 200 miles. In 2004, police patrolling it found a fully equipped secret cinema, complete with a bar.
Seattle's original downtown is still down there — the city just built a new one on top of it.
After the Great Fire of 1889, Seattle regraded its streets up to a full story higher, leaving the old sidewalks and storefronts buried beneath Pioneer Square. You can still spot the purple glass prisms in the pavement that once served as skylights for the world below.
Derinkuyu, an 18-level underground city in Turkey, was rediscovered in 1963 when a man knocked down a wall in his basement.
The city plunges about 85 meters into the rock of Cappadocia and could shelter thousands of people, complete with stables, chapels, and wells. It even connects by tunnel to a neighboring underground city.
In the 1850s and 1860s, Chicago jacked its entire downtown out of the mud — buildings, streets, and all.
To install sewers above the swampy ground, crews raised whole city blocks on thousands of jackscrews, sometimes several feet at a time. The Briggs House hotel was lifted while guests stayed inside, reportedly without cracking a window.
In Coober Pedy, Australia, roughly half the town lives underground.
Summer heat in this opal-mining outpost is so brutal that residents carved their homes — plus churches, hotels, and shops — into the cool rock. The town's name supposedly comes from an Aboriginal phrase glossed as 'white man in a hole.'
Poland's Wieliczka Salt Mine contains chapels carved entirely from salt — including the chandeliers.
Miners worked the deposit from the 13th century and spent their spare hours sculpting the astonishing St. Kinga's Chapel, where even the crystal chandeliers are reworked rock salt. It was on UNESCO's very first World Heritage list in 1978.
Cincinnati has miles of subway tunnels that never carried a single passenger.
Construction began in 1920, but money ran out and the automobile took over before the system opened, leaving one of the largest abandoned subway projects in America under Central Parkway. The city still maintains the empty tunnels a century later.
Naples sits on a honeycomb of Greek quarries, Roman aqueducts, and World War II bomb shelters.
The digging started around the 4th century BC, and by WWII the same cavities were sheltering thousands of Neapolitans from air raids. One tunnel, built as a royal escape route for the Bourbon kings, now houses a collection of vintage cars abandoned underground.
New York's most beautiful subway station has been closed to the public since 1945.
The original City Hall station opened in 1904 with vaulted Guastavino tile, chandeliers, and skylights — then closed when longer trains couldn't fit its curved platform. Riders who stay on the downtown 6 train as it loops around can still glimpse it.
Tokyo hides a flood-control cathedral 50 meters underground, nicknamed the Underground Temple.
The Metropolitan Area Outer Underground Discharge Channel, completed in 2006, funnels floodwater into a vast tank held up by 59 pillars weighing about 500 tons each. It exists so that Tokyo's streets don't become rivers during typhoon season.
Respect to Chicago for deciding the fix for bad drainage was to simply lift the city — while people were still checked into the hotel.
