For some people, travel in Europe means seeing the glories of the great cities: the Louvre in Paris, perhaps, or the Sistine Chapel in Rome. Others prefer muddy trenches.

"The point to coming here," retired British Army Maj. Tonie Holt tells the 45 people following him on a tour around Ypres, Belgium, the site of heavy fighting in World War I, "is to see and hear what you can't get from the printed page."

The people in the trenches -- many of them frequent customers of Holt's Battlefield Tours -- certainly couldn't get the ankle-deep muck from the printed page. After peering obediently through the midnight darkness at a former enemy position, they get a signal that tells them to creep through the forest to a bivouac, where they take tea. Then it's back to the hotel.

Holt and his wife, Valmai, enliven another stop by reading personal accounts of soldiers who fought in battles covered in the five-day tour, playing cassette tapes of music from the era and passing around period photos and newspaper clippings. They also talk about what it's like to sleep in a trench and face poison gas.

The Holts started their business almost by accident about two decades ago, when a book they wrote on World War I prompted a military book club to ask them to conduct a tour. Now they can accommodate interests ranging from the battles of Cre'cy and Agincourt in the Hundred Years' War to the Vicksburg campaign of the U.S. Civil War to the Falkland Islands conflict. Business is so brisk that some tours are booked two years in advance.

"It's sheer luck," says Holt. "We're doing what we like."

"I've been on other battlefield tours," says Philip Guest, a retired bank auditor from Salisbury, England. "But they weren't as well organized. The Holts have studied it." Guest, who is on his 14th tour with the Holts, admits, "It is a very strange hobby."

One couple celebrated their honeymoon by starting with a Holt tour of Somme River battlefields, in northern France, then moving on to the Ypres tour.

Alan Colley, a 32-year-old passenger-service representative for British Airways, has taken 16 Holt tours in the past seven years, with an emphasis on World War I. "People at work think I'm crazy," he says. "I can get free tickets and go to Barbados and lie on the beach. Instead I spend my time in cemeteries and climbing over barbed-wire fences." For more information, contact Holt Battlefield Tours, Golden Key Building, 15 Market St., Sandwich, Kent CT 139DA, England, phone 612-248.