"I'm so excited I can hardly speak," gasped Freddie as we rolled up at the reception desk. "Can I go to sleep cuddling a shark?" asked my daughter Catriona. The two seven-year-old girls couldn't have been more thrilled to be checking in to what must be the most unusual place in town to spend a night. However, I was a little unsure of how comfortable a night on the floor of an aquarium could be.
While you can't actually cuddle the cold-blooded Jaws-a-likes at the sleepover at the National Marine Aquarium in Plymouth, you can roll out your sleeping bag against their tank and fall asleep staring into their eyes, if you dare.
The events happen regularly but are rarely fully booked; on our visit there were about 20 children staying, though the aquarium has the capacity for more.
There was an action-packed evening ahead: aquatic ice-breaker games, swiftly followed by a tour of the aquarium, all the more magical when it's dark outside and the children have got the entire place to themselves. The highlight for the kids I took along was the enormous shark tank - 10 metres deep, holding an astonishing 2.5 million litres of water, one of the biggest fish tanks in Europe.
"Sharks are shy," said Karlie Bertram, our host, "so we'll all have to be really quiet before they'll come to this side of the tank." Sure enough, it took ages and a lot of shushing before a shark eventually floated gently past, wowing Freddie and Catriona. But that's the beauty of an aquarium sleepover - we could have waited all night, if we had to, to see the fish we really wanted to spot. Catriona's favourites were the clown fish - "the colours are so cool" - while for Freddie the rays were pretty stunning, despite some fairly graphic detail from Bertram about how Steve Irwin met his end. Then there were the poisonous blue-ringed octopus, which all the kids regarded with solemn respect. Apparently it has the potential to kill off the aquarium staff if they get too close at feeding time, and there's a huge alarm bell on the wall in case of attack.
Who'd have believed so many dangers were lurking in an aquarium - or that the cinema would hold so many surprises? "Best leave your tape recorder at the door," Bertram told me. I couldn't think why - until, just as the turtle in the cartoon was being cornered on the big screen, a sharp jet of water hit me straight in the chest, while the seat lurched sharply backwards. "Awesome," was Freddie's verdict. "I've never been in a 4D cinema before!"
Next it was the arts and crafts room and the chance for everyone to draw or paint their favourite fishes. By 10pm the adults were exhausted - but the kids were still raring to go. "Let's get out our sleeping bags," suggested Bertram - and, as if by magic, a huge film screen descended in front of the main fish tank.
Three hours and two films later most of the mob were snoring gently away, but there were still a few diehard kids sitting up in their makeshift beds, mesmerised by the fish swimming past. "They didn't go to sleep, so nor did we," 11-year-old Alicia told me the following morning. But those who did sleep loved the experience of seeing fish lapping by as they roused themselves from their dreams.
At breakfast, the panorama of Plymouth's historic waterfront was laid out in front of the aquarium's cafe, and Freddie, Catriona and I munched our bacon sandwiches, mesmerised by the view.
• Visit national-aquarium.co.uk. Whether you accompany your kids to the sleepover is optional
More sleepovers
National Media Museum, Yorkshire
Budding media types can try their hand at movie-making, animation and photography at evening workshops and spend a night sleeping in one of the galleries. They wake up to an Imax film in the cinema.
• National Media Museum, Bradford; 0870 7010200
nationalmediamuseum.org.uk
Paignton zoo, Devon
Kids hunt for bats using hi-tech detection equipment while exploring the zoo at night, then see the animals eating their breakfast in the morning. Children don't need to be accompanied by an adult.
• Totnes Road, Paignton; 01803 697500
paigntonzoo.org.uk
Golden Hinde, London
Get into Tudor costume, then spend the evening learning how to be a gunner, officer or barber-surgeon on board the 16th-century replica ship. A stew for dinner is followed by bedtime stories, and families sleep on the gundeck between the cannons.
• St Mary Overie Dock, Cathedral Street, SE1; 020-7403 0123
goldenhinde.org
Science Museum, London
Children take part in workshops and watch shows, and then spend the morning watching a 3D film at a Science Night sleepover at the museum.
• Exhibition Road, SW7; 0870-8704 868
sciencemuseum.org.uk
Perri Lewis
