For a different view of Monaco.
There's an area of Monaco hidden from the beautiful blue skies. The Observatory Grotto is a series of underground chambers that a few thousand Jardin Exotique ticket-holders visit every year. For the adventurous, the Monaco Speleo Club (pot-holing and caving) organizes free visits to parts of the grotto not normally open to the public.
Each visit can accommodate 5 to 7 people over the age of 12. You'll be provided with suits, helmets and harnesses, and should wear an old pair of gloves and shoes. The journey involves entering the grotto by ladder, and using ropes to descend 60 meters through tunnels and caves. You eventually arrive in a large cavern that's somewhere near Place d'Armes. Unfortunately there's no exit here, so you have to make your way back uphill to the entrance.
Club members say there's no great danger, it's very safe and is a good initiation into caving and pot-holing. If you're interested, contact the Speleo Club of Monaco on 06 61 84 36 28.