Turning away the under 60s

Many are widows or widowers looking for some company and mild flirtation, and anyone under 60 is turned away as they may "annoy other patrons and spoil the mood," Lee says.

The dress code is generally conservative, with men in pleated pants and blazers and women in dress pants or knee-length skirts.

Some women might risk a shorter hemline, or a bit of glitter, but for the men, a fedora worn at a jaunty angle is about as risque as it gets.

In what remains a very Confucian culture, elderly South Koreans are expected to behave with moderation and dignity, and Colatecs are frowned on by those who see them as unseemly hook-up joints for pensioners.

As a result, patrons like Han Keum-Ok, a 75-year-old Kukilgwan regular for the past 10 years, keeps her hobby a secret.

"My children and grandchildren think that I just meet my friends over coffee or lunch," said Han, who dances every afternoon away before returning home to cook dinner.

Han says the routine has kept her healthy and happy while many of her non-dancing friends have suffered depression or illness.

"At my age, you never know how long you will live, and I'd like to enjoy the rest of my life to the full.

"But I tell no one I come here because a lot of people think Colatecs are immoral," she says.