The parent site consists of: two main research sites (Lake Santo Parmense and Lake Scuro Parmense) in the Northern Apennines, but also several temporary and permanent lentic systems sampled at a lower frequency; two main research sites in the Western Alps (Lake Paione Inferiore and Superiore), and about 30 high altitude lakes (above 1900 m a.s.l.) in the same area, with long-term irregular data; one research site located in the Brenta Dolomites (Lake Tovel) at 1178 m a.s.l. with a monthly sampling regime and long-term data; three main research sites in the province of Bozen, together with other 11 lakes all located below the treeline, monitored since 1979 with samplings at irregular intervals. For all the main research sites long-term data exist on water chemistry, plankton and benthos; however, the datasets of the various sites may be different in terms of size, temporal coverage, frequency of the series and monitored parameters. The main research topics considered are eutrophication and acidification, population dynamics, biodiversity, functional diversity, lake metabolism, plankton phenology, alien species, climate change effects, impacts of anthropogenic activities in lake catchments, high frequency monitoring.