Fourteen tanks filled with hundreds of different plant, fish and mollusk species including moray eels, sharks, sea horses, lobsters, octopi and other fascinating creatures.
But these gorgeous species aren't just thrown into the water willy nilly. This aquarium strives to recreate the coastal environments from which these species come from. Surprisingly, this not only includes the waters around Porto Santo Stefano and Monte Argentario, but the Mediterranean Sea as well.
The learning centre inside the aquarium aims to raise awareness about the environmental issues that the Argentario Coastline in particular faces.
It uses videos and sound displays to provide us with a glimpse into underworld life and educate us about the damage we're inflicting on our oceans everyday.
You can also take a guided tour of the aquarium and the adjacent laboratory.
Address: Lungomare dei Navigatori 44, Porto Santo Stefano
Oct-May: Tue-Fri: 3pm to 7pm. Sat-Sun: 10.30am to 12.30pm and 3pm to 7pm
Jun-Sept: Tue-Fri: 4pm to 10pm. Sat-Sun 10.30am to 12.30pm and 4pm to 8pm
Jul-Aug: 10.30am to 12.30pm and 5pm to midnight every day except Mondays
Entry price: Adults: € 4,50. Children (6 to 12): € 1. Children under 5: free
For more info: visit the official Maremma museums website.