Question: In "A Short Drink from a Certain Fountain," the experimental youth serum alludes to what famous spring?

Context paragraphs:
CHYDARU: CHYDARU, unabbreviated name Chapel Hill Youth Development and Research Unit, is an experimental youth prison operated by the Institute of Government at the University of North Carolina at Chapel Hill and the North Carolina prison system.  Built in 1945, it opened as a prison for youth under the age of 18 on May 1, 1964.  The project was as an advancement in prison structure.  It closed later in 1965 due to budget shortages.  Sometime during the 1970s it housed the Bureau of School Services, which was operated by UNC.  Later in 1975, it was repurposed to store radioactive waste.  It is inspected annually by the government to monitor the waste.

A Short Drink from a Certain Fountain: "A Short Drink From a Certain Fountain" is an episode of the American television anthology series "The Twilight Zone".  In this episode, a scientist gives his brother an experimental youth serum in order to save his marriage to a much younger woman.  The episode's title refers to the mythical Fountain of Youth.

Barry-Roubaix: Barry-Roubaix is a classic-style road/off road cycling race featuring a variety of terrain and surfaces to test cyclists of all skill levels.  The course is located in Barry County, Michigan near the Gun Lake Unit of Yankee Springs Recreation Area.  Most years, Barry-Roubaix consists of rolling gravel roads (80%), pavement, one mile of rough two-track, rocks, sand, mud, and possibly snow and ice, along with 2200 feet of climbing.  The race features three distinct levels of competition corresponding to different race course distances.  The Beginner/Intermediate riders complete a 24-mile course, the Expert riders complete a 34-mile course, and the Elite/Pro riders complete a 62-64 mile course.  The name "Barry-Roubaix" was selected in a naming competition; it is a reference to the famous spring classic Paris–Roubaix one day professional cycling race held in France.  Barry-Roubaix is held annually on the fourth Saturday in March.  Participants use a variety of bicycle types (cyclocross, mountain, road, fat), depending on course conditions and individual preferences.

Jackson's Valley Campaign: Jackson's Valley Campaign was Confederate Maj. Gen. Thomas J. "Stonewall" Jackson's famous spring 1862 campaign through the Shenandoah Valley in Virginia during the American Civil War.  Employing audacity and rapid, unpredictable movements on interior lines, Jackson's 17,000 men marched 646 miles (1,040 km) in 48 days and won several minor battles as they successfully engaged three Union armies (52,000 men), preventing them from reinforcing the Union offensive against Richmond.

Walter de Camp: Walter de Camp (born "Kari Lempinen"; d. 5 April 2017) was a Finnish writer.  He wrote about partying, restaurants and celebrities in the Finnish City magazine.  There is also a drink named Walter de Camp after the writer.  It was designed by Jasu Piasecki after the short description given by the writer: "It has to contain whiskey, be a short drink and taste really good."

Khwaju Kermani tomb: Khaju tomb is located in north of Shiraz, on the hillside Sabooy and Road Shiraz - Isfahan in a narrow Allahu Akbar Gorge.  His grave overlooks the Qur'an Gate.  Roknabad famous spring water also passes near the tomb Khaju.  The tomb was built with the Funding Department of Culture of fars in 1315 Solar.  Tomb is located in Enclosure without roof.Its headstone is in the middle of the platform that its above is convex and has a bulge.there is not any Inscription that represent the Khaju grave.Only on stone is written this sentence کل من علیها فان و یبقی وجه ربک ذوالجلال و الاکرام .

Vaucluse: The Vaucluse (] ; Occitan: "Vauclusa" in classical norm or "Vau-Cluso" in Mistralian norm) is a department in the southeast of France, named after the famous spring, the Fontaine-de-Vaucluse.  The name Vaucluse derives from the Latin Vallis Clausa (closed valley) as the valley here ends in a cliff face from which emanates a spring whose origin is so far in and so deep that it remains to be defined.

Ruta Lee: Ruta Lee (born May 30, 1935) is a Canadian actress and dancer who appeared as one of the brides in the musical "Seven Brides for Seven Brothers".  She had roles in films including Billy Wilder's crime drama "Witness for the Prosecution" and Stanley Donen's musical comedy "Funny Face" and also is remembered for her guest appearance in a 1963 episode of Rod Serling's sci-fi series "The Twilight Zone" called "A Short Drink from a Certain Fountain".

Thomas Witlam Atkinson: Thomas Witlam Atkinson (1799–1861) was an English architect, artist and traveller in Siberia and Central Asia.  Between 1847 and 1853 he travelled over 40 000 miles through Central Asia and Siberia, much of the time together with his wife Lucy and son Alatau, who was born during their travels.  He also painted and documented his travels in two books that are today regarded as travel classics.  His and Lucy's son, Alatau Tamchiboulac Atkinson, born on 4 November 1848 in what is now Eastern Kazakhstan, was named after a famous spring in the town of Kapal at the foot of the Djungar Alatau mountains.

Fountain of Youth: The Fountain of Youth is a spring that supposedly restores the youth of anyone who drinks or bathes in its waters.  Tales of such a fountain have been recounted across the world for thousands of years, appearing in writings by Herodotus (5th century BC), the Alexander romance (3rd century AD), and the stories of Prester John (early Crusades, 11th/12th centuries AD).  Stories of similar waters were also evidently prominent among the indigenous peoples of the Caribbean during the Age of Exploration (early 16th century), who spoke of the restorative powers of the water in the mythical land of Bimini.

Supporting paragraphs: A Short Drink from a Certain Fountain Fountain of Youth
Answer: Fountain of Youth