At the Sink, the writing's on the wall. And on the ceiling, too. With just about every square inch from the ground up covered in ink, new visitors and established "Sink Rats" can scrawl their thoughts or find new reading material to accompany their brews every night. Established in 1923 as the Sunken Gardens, "The Sink" (nicknamed for a low-lying fountain) was officially renamed in 1949; today this mural and graffiti-art haven is also the epicenter of CU's social pulse.

The Scene: While the low ceilings are an open canvas for anyone with a Sharpie, the Sink's walls are off-limits to amateurs. There you'll find the beatnik artwork of Mike Dormier and Llloyd Kavich, including Sinkstine Chapel (which shows the exchange of the classic Sinkburger from man to God) and a portrait of the Sink's most famous Rat and star janitor: Robert Redford. While attending CU in the 1950s, Redford officially worked and (according to legend) played at the Sink, too.

A good atmosphere and a prime location (it's a five-minute walk from campus) have made this joint one of CU's rowdiest bars. "It can definitely get crazy in here at times," says Laura, a senior majoring in marketing, "but it's also cool just to chill and check out the walls." Consensus is that if you don't go to the Sink, you really don't go to CU -- the place even has its own graduation. Starting at 7 a.m. on commencement day, seniors are invited to partake in the Sink's own parting ceremonies. Complete with Sink diplomas and speeches, the bar bids goodbye and good luck to its new class of Sink Rats. No wonder nostalgic alumni and lifetime Rats make pilgrimages back year after year.

Chicks at the Sink: As a bar spitting distance from the Greek houses, the Boulder sorority presence is blatant. But Greek or not, CU girls know how to get rowdy. "The girls can be pretty scandalous," says Daniel, a senior majoring in economics and English. "You never know what's going to happen inside this place."

When to Go: For the broke college student, Monday starts the week off right with "Flip Night": flip a coin for a drink, call it, and it's only a quarter. On football Saturdays, The Sink is the loyal Buffs fan's cure for Folsom Field's prohibition. Herds of black and gold descend upon The Sink starting at 9 a.m. and prepare for game time. For home games, the convenience of the 10-minute stumble to Folsom for the first half is only surpassed by the quick jog back at halftime to keep spirits and blood-alcohol levels high.

Dress Code: Laid-back girls in jeans and T-shirts are fixtures, but on Monday and Tuesday nights The Sink attracts sorority girls with a bit more style and skin. For guys, the fraternity uniform of jeans and a button-down Polo shirt is a safe bet. Fall Saturdays require gold apparel; douse yourself in body paint and you'll be the most popular guy there.

At the Bar: Mondays, Flip Night. Tuesdays through Saturdays, $2 wells. Sundays, $2 Bloody Marys and screwdrivers. Be sure to try the "Rat Poison" (a mix of Absolut Kurant, Grape Pucker and sour mix topped with soda water) and "In the Buff" (Bacardi Limon, Peach Schnapps, Grand Marnier and sour mix). The low ceilings make Thursday's Beer Pong night a challenge of ultimate skill and accuracy, but the $4 pitchers make it all worth it.

Where It's At: 1165 13th St., Boulder, Colorado

Hours: 11 a.m. - 2 a.m. Restaurant closes at 10 p.m.

Phone: (303) 444-7465

Website: www.thesink.com

Text by Carolyn Matthews
Photos by Kent Conklin