The central nucleus of Passignano was built upon a rocky spur that forms a small promontory that descends to the lake.
The background with an altitude from 255 to 706 mts. a.s.l. is mostly hilly and rich in sub-Mediterranian vegetation.
Oak species are the most common trees with dryland woods and heliophilic plants dominating the banks with white willow, marsh cane and "mezzasorda".
The mid-hill faces the lake and is planted with grapes and olives, while on the plains there are broad grassland areas.
The fauna is very interesting, especially the aquatic birds.
It includes coots, "cannareccione", reedling, reed sparrows and bitterns.
Great-crested grebes, little grebes, herons, lapwings, gulls and ducks stop at the lake during migration.
There are 18 different fish species including pike, tench, queencarp, royal perch,
eel and "latterino".
The waterways flow mostly in the winter and the climate is particularly mild because the area is protecdet from the north wind by the hills.