Tallinn has been something of a soft touch for invading hordes over the centuries. Just about every nation or clan that borders the Baltic Sea has at one time or another approached the city's imposing, yet clearly breachable walls - Vikings, Danes, Swedes, Poles, Nazis and Soviets. Poignant dates litter this small country's history : 1346, when the city was sold by the Danes to the Teutonic Order ; March 9 1944, when the Nazi-held city was bombed remorselessly by the Soviets throughout the night ; August 20 1991, when Estonia finally regained independence from the Soviets after the so-called Singing Revolution.
But a more recent date may come to be noted as a turning point for the city - October 31 2004. This was when the first easyJet flight from Britain landed at Tallinn's airport. Some feel the city has never been the same since. For around £40 each way, the journey to Tallinn's medieval old town - a Unesco world heritage site - became instantly affordable to Britons. The state airline, Estonian Air, soon dropped its prices to compete.
Before this date, most Britons visiting the city were over 50 and largely interested in culture and architecture. Beyond Tallinn itself, other attractions proved popular : the limestone cliffs at Ontika; the coastal spa town of Pärnu; the forested and bog-filled nature reserves ; and the large islands of Hiiumaa and Saaremaa to the west. But since Tallinn became cheaper to reach it has joined the ranks of European cities that each weekend have to deal with sometimes hundreds of drunk, leery men , singing and stumbling their way from bar to strip club in search of alcohol and sex, under the banner of the stag party. Of all these cities, Tallinn is seen to be particularly vulnerable to this form of tourism as, unlike the bigger cities that these "staggers" head to, the downtown area is little more than a mile wide. In such a small space, the staggers more than make their presence felt.
In the shadow of Toompea Castle, just 10 minutes' walk from the city's medieval heart, I am breakfasting on ham, cheese and rye bread while behind me three British men in their late 30s - the first to emerge from bed out of a group of staggers a dozen strong - talk about the night before. "You've got a McDonald's, bars and a strip club on one street. What more could you want?" asks one. Another switches on his digital camera and begins to show his friends some photographs taken the night before. "She's a cracker, isn't she ? I'm going to ring her tonight. I think I'm in love." At the next table, a middle-aged couple from Germany tut under their breath.
Later, as the sun drops beneath the city walls, Tallinn's old town begins to swell with tourists looking for an evening meal. Many congregate first in the bars that line the town square, where the only original Gothic town hall in northern Europe still stands, unchanged since 1429. Within a few hundred metres are most of the bars and clubs frequented by the staggers, with beers on tap and live football on big screens. All of them are packed with men shouting at the screens, singing en masse, or sinking pints. Within a few hours many of them will be making their way to the strip clubs and nightclubs near by.
Just five minutes' walk away, I meet Dr Nelli Kalikova in the lobby of the 1930s Scandic Palace Hotel. From 1996 to 2003 she was the head of Estonia's Aids prevention centre, before deciding to enter politics as a member of parliament. She is outspoken about the rise of these stag parties and, in particular, the fact that a visit to the city's prostitutes is often part of their itinerary. "The men on stag parties drink like pigs," she says. "They come here just to buy sex. About 30% of the girls' clients refuse to wear condoms. They pay more for this 'privilege', or they do tricks like pulling it off at the last minute. It is kamikaze sex."
Kalikova says there is a 5% infection rate among the prostitutes in the city when it comes to HIV/Aids, but this is increasing as more and more of the women become drug addicts. And she is convinced that staggers don't know the risks they are taking. A survey of prostitutes that was conducted in 2005 by the Estonian Institute for Open Society Research paints a picture far worse than even Kalikova suggested: one in every five prostitutes surveyed tested positive for HIV and one in five also suffered from "uncured venereal diseases". At least 85% of the prostitutes were 30 or under. The stag trips both greatly swell demand and lend a veneer of acceptability to the fact that many of the prostitutes and "dancers" are women trafficked across borders by criminal gangs.