SINCE ITS renovation, the Main Hall of Union Station has become one of this city's most aesthetically pleasing places in which to stroll, dine and people-watch. So it was an inspired idea for the powers that be over at Dance Place -- Washington's most prolific and adventurous presenter of dance events -- to celebrate the organization's 10th anniversary by temporarily transforming the Main Hall into a performance space.

"Union Station Dancing," which opened Thursday and repeats Friday, is a free, highly unconventional program that is as much about the balconies, fountains, staircases and other architectural features of this historic building as it is a showcase for the imaginative group of local and out-of-town musicians and dancers that Dance Place has assembled.

Senegalese music master Djimo Kouyata will get things rolling with his virtuosic playing of the 12-stringed kora. Liz Lerman and the Dance Exchange, plus 100 additional "friends," will offer a large scale presentation that, judging from Lerman's previous spectaculars, is sure to elicit many a gasp and giggle. Other choreographers contributing to the festivities are Marta Renzi and her Project Company -- dancing in the fountain! -- and a pickup company directed by Stephan Koplowitz and accompanied by the much-lauded Eastern High School Choir.

The performance will in no way impede the flow of pedestrian traffic. Rail passengers, dance lovers and anyone else just happening by can all share in this freewheeling ode to art and architecture.

If Renzi's "fountain creation" at Union Station tickles your fancy, you might also want to catch her New York-based troupe's performances at Dance Place Saturday and Sunday. One of the cleverest, most irreverent dancemakers around, this curly-haired sprite has crafted works about adolescent and adult love and lust, pornography versus eroticism, and other provocative topics. Her use of music -- be it Springsteen, Otis Redding or Sacred Harp Singing -- is always right on target, and her movement has an easy, sensual quality to it. It's the kind of dancing that you feel you might be able to master if given half a chance.

Renzi's program here will include "Joy and Her Daughters," a tribute to the choreographer's early teacher and mentor, whose cast consists of a 7-year-old girl and her dancer/mother plus Village Voice dance critic Deborah Jowitt. "Loco Parentis" features five men, Renzi's father and brother among them, while the solo "The Penguin Dictionary of Science" puts Renzi herself in the spotlight. Also on the program: the male quintet "Sacred Harp" and the duet "I'm Looking Through a Book of Indian Minatures."

UNION STATION DANCING -- Friday at 7, Main Hall of Union Station, First Street and Massachusetts Avenue NE. Call 202/269-1600.

MARTA RENZI & THE PROJECT COMPANY -- Saturday at 8, Sunday at 7 at Dance Place, 3225 Eighth St. NE. Call 202/269-1600.