The earliest known roller coaster debuted in Paris in 1817, built by French inventor Louis Séguin. While contemporary illustrations may exist, the oldest surviving coaster is the Leap-The-Dips, a wooden side-friction coaster opened in 1902 at Lakemont Park in Altoona, Pennsylvania. Photographs and postcards of Leap-The-Dips are widely available online and in historical archives. For the 1817 Paris coaster, search for "Promenades Aériennes" or "Russian Mountains" in digital collections of the Bibliothèque nationale de France or early 19th-century European prints.