The official recognised length is 175 metres, but many measurements show several metres less.despite its length, it is a real river, not just a stream, as it has its own source and bed and empties into Lake Garda.

Interesting facts about the Aril
- It rises in the village of Cassone (near Malcesine) and flows through its centre.
- During its short journey it crosses three bridges and even has a small waterfall.
- The river is regulated and in winter its flow is sometimes adjusted to stabilise the level.
- In December, a small Christmas nativity scene is held on the river, a popular local tradition.
- A small lake has been created in one place, which serves as a natural refuge for trout, which regularly return to spawn here - there is a strict no-fishing rule on the river!