Abstract
The largest French speleological networks have been explored in the French mountains (Alps and Pyrenees). They combine considerable depths and total lenghts (8 netwoks exeed -1000 m, 92 exceed -500 m, nearly 50 networks are longer than 10 km). They present a wide morphological diversity and interest for reconstructions of the past. Through seven outstanding examples published in the last two decades, we propose here an overview of these karsts around four themes: identification of remnant high-altitude levels, cave levels, glacial heritage, and recent environmental records.