Warm light bathes an alley in London, England. It shines from gas-powered lamps—and has for hundreds of years.

These lamps are the last of their kind. Time marches on. People put in electric lamps instead.

Wait a minute! some Londoners think. Leave our gas lamps alone!

“Gas lamps are very much part of London’s DNA,” says Luke Honey. He co-founded the London Gasketeers, a group set up to protect the last of the lamps. “They’ve been immortalized on television, in film, in books, in literature . . . They deserve to be saved.”

City officials disagree. They have begun replacing the old lamps with LED versions. Bookseller Tim Bryars was horrified when work started on the street lamp outside his shop. He counts on the gas lamps—not just for light, but for business. People come to his street just to experience the gas lamps. The lamps remind people of old times when lamplighters would come along every morning on their bicycles, ladders over their shoulders, to extinguish lamps.

But officials say replacement lamp parts have become hard to find. And if the lights go out and can’t be repaired right away, the streets aren’t as safe. Besides, they say, the new electric lights are more environmentally friendly.

But the lights’ caretakers, a specialist team from British Gas, say the lamps have plenty of spare parts. The gas lamps use very little gas. And installing new lights means digging up the street to connect them to power.

So far, officials have replaced 10 percent of the gas lamps. Will they do more? Not for now. Lamp lovers’ complaints have made them push pause.

Why? Nostalgia is a feeling of fond longing for a place or period one knew before. It reminds us we’re made for a perfect home with God.