Saturday was the last day of my daughters holiday at the Brittany holiday cottage with private heated swimming pool and we decided to leave early at 8 am to visit whats reputed to be the biggest aquarium in Europe Oceanopolis, based in Brest.
Her flight was from Brest at 4.15 and arriving at Oceanopolis at 10.30 we had plenty of time to visit as it states on its website you need half a day....we finished at 12.30
I must admit I was expecting so much more than what we got, the actual floor space of Oceanoplolis was large but the gaps between each exhibit was also quite large and the majority of the tanks pretty standard. The best part was the shark tank and in particular a glass sided lift that started at the top of the tank and slowly descended to the bottom of the tank.
In between the tanks were loads of interactive videos and computers but alas they were all in French, I think for the French it would have been alot better experience being very educational for the children.
The cost of entry was 16 euros for an adult and 11 for a child, so not a cheap 2 hours of entertainment and I'm glade I did not make the trip just for the aquarium, but more for my daughters flight and to ' kill to birds with one stone'.
To summarize given what I experienced and the cost, plus the distance, the aquarium at Vannes just 25 min away from la Forge is the best option.