We have been taking a look at the 10366 Tropical Aquarium, coming out in mid November 2025. This is a large, expensive set, quite unlike anything that the LEGO Group has produced at this scale before. It’s not based on a renowned piece of Architecture, it doesn’t tie in with any preconceived cinematic universes, and neither does it follow up with one of the regular ICONs subthemes. It’s a 52 litre fish tank, filled with corals, plants, and fish of unrealistic provenance. However, I must admit, it looks quite neat. Impressive even.

Fish tanks often feature decorative elements within them. The Tropical Aquarium features a treasure chest, tucked away in the back corner, serving as a bubbler, along with a rock cave and shelf. However, beyond that, it is comprised of all plants, coral, and anemones.

In fact, it’s beginning to look like one of those colourful underwater layouts you often see at LEGO Conventions, with lots of hidey holes and scope for exploration and storytelling. This left me thinking about the broad range of underwater exploration themes that have cropped up over the years, and more importantly, made their way into my collection. And how they could add life to this set.

Let’s start with a quick look at some of the sets which I own (and some that I don’t), which feel as though they might serve as aquarium decorations .

1. A Brief History of Underwater Themes
   1. Aquazone
   2. 1997-2012: Divers, Alpha Team, Aqua Raiders and Atlantis
   3. LEGO City Deep Sea/ Polar Explorers
   4. LEGO IDEAS
   5. SpongeBob SquarePants
   6. The Little Mermaid
2. Let’s consider the space that we are planning to customise.
3. Filling the Aquarium
   1. SpongeBob Square Pants
   2. Yellow Submarine
   3. Fantasy Underwater Layout: Enter the Aquazone
      1. Action Stations
4. In conclusion