About 2km west of Żurrieq lies the tiny harbour of Wied iż-Żurrieq, set in a narrow inlet in the cliffs and guarded by a watchtower. Here, boats depart, weather permitting, for enjoyable 30-minute cruises to the Blue Grotto, a huge natural arch in the sea cliffs 400m to the east.
The boat trips also take in seven caves, including the Honeymoon Cave, Reflection Cave and Cat's Cave.
The best time is before mid-morning, when the sun is shining into the grotto. If there is any doubt about the weather or sea conditions, call to check.
You can see the Blue Grotto without a boat from a viewing platform beside the main road, just east of the turn-off to Wied iż-Żurrieq.