Spluga della Preta, Natural cave system in Sant'Anna d'Alfaedo, Italy

Spluga della Preta is a karst shaft in the Pialde area of Sant'Anna d'Alfaedo, just north of the Corno d'Aquilio summit. Its entrance is a large oval opening in a steep grey rock face, with an overhanging brow and moss patches around the rim. The cave descends 877 metres through vertical shafts and chambers.

Enrico Nicolis, president of the CAI of Verona, described the entrance in 1898. In 1901 Giovanni Cosser of Ala estimated the first shaft at 500 metres, and in 1909 the CAI published the correct figure of 129 metres. The first expedition descended only the main shaft in 1925; two years later a CAI team reached 376 metres but claimed 637 metres and the bottom, so the cave was renamed Abisso Benito Mussolini and held a false world depth record until 1953.

Multiple international spelunking teams, including groups from Belgium, England, and Poland, regularly conduct research expeditions in this vertical cave system.

The entrance lies in the Pialde area, the last strip of Verona province before Trento, just north of the Corno d'Aquilio summit. Reaching the cave requires a hike and vertical caving with ropes; the first shaft alone drops 129 metres. The site has been heavily visited for over 60 years, and the 1988–1992 Corno d'Aquilio operation removed more than four tonnes of waste left by earlier expeditions.

The Sala Nera was reached on 10 July 1963 by Giancarlo Pasini and Gianni Ribaldone after a risky 25-metre descent, and for 18 years it was taken as the cave's bottom. In December 1981 Franco Florio and Olimpio Fantuz found a window near its vault, leading to the Fondo Nuovo; later surveys placed the Sala Nera floor at 777 metres and the cave's depth at 877 metres.