Voulismeno Aloni is a very weird geological phenomenon. It is a very large circular ground sinking (doline), with approximately 50 metres depth and 90 metres diameter, which has been shaped after a cave’s fall and now is ideal for climbing.

Voulismeno Aloni is visible from the road that connects Heraklion and Rethymno and is located 15 kilometers west of Heraklion near the Marathos village.

Voulismeno Aloni means threshing floor that has sank and is based on a folk story.