The construction of the Jungfrau railway in the early 20th century, which connects Kleine Scheidegg to the Jungfraujoch, the saddle between the Mönch and the Jungfrau, made the area one of the most-visited places in the Alps. Along with the Aletsch Glacier to the south, the Jungfrau is part of the Jungfrau-Aletsch area, which was declared a World Heritage Site in 2001.