Lake Albano (called Lake Castel Gandolfo) and Lake Nemi are two basins of volcanic origin. The first is the deepest in Lazio – it reaches 168 meters. The second is smaller but higher by 25 meters. They have no natural tributaries or outfalls-they are fed by two of the most important hydraulic works in the region. Inhabited since prehistoric times, they are home to archaeological sites of incredible value, such as Neolithic settlements and ancient villas.

Also notable is their naturalistic value in terms of flora and fauna. Their ultra-clean waters offer two different bathing experiences: Lake Albano also has equipped beaches, while Lake Nemi is wilder. The latter is famous for growing wild strawberries.