Sunken Colossum – Hidden Observation Cave | Aquarium & Terrarium Decor

Uncover ancient mysteries in your aquarium with the NEW! Sunken Colossum Hidden Observation Cave – a timeless sanctuary where your aquatic companions can retreat, relax, and rule their domain from the shadows. Designed for plecos, shrimp, beetles, or even small reptiles, this sculptural hideaway offers both function and fantasy in equal measure.

With its weathered stone look and arched contours, the Sunken Colossum adds a touch of submerged history to your aquascape. It’s more than a hideout; it’s a stage for curious crawlers and shy swimmers to peek out, plot their next move, and feel at home.

Bring ancient charm and cozy security to your tank with this handcrafted escape tunnel. Whether your critters are hiding or just observing, the Colossum is where legends begin. 🐟🏛️

🌟 Brand New! Part of our Lost World Collection.

📏 Available Sizes (L x W x H)

• S – 16.1 × 11.4 × 6.4 cm (6.3 × 4.5 × 2.5 in)
• M – 19.1 × 13.6 × 7.6 cm (7.5 × 5.4 × 3.0 in)
• L – 25 × 17.8 × 10 cm (9.8 × 7.0 × 3.9 in)
• XL – 27.5 × 19.6 × 11 cm (10.8 × 7.7 × 4.3 in)
• XXL – 30 × 21.3 × 12 cm (11.8 × 8.4 × 4.7 in)

🕳️ Top Opening

• S ~ 3 – 9 cm (1.2 – 3.5 in)
• M ~ 4 – 11 cm (1.6 – 4.3 in)
• L ~ 5.5 – 14.5 cm (2.2 – 5.7 in)
• XL ~ 6 – 16 cm (2.4 – 6.3 in)
• XXL ~ 6.5 – 18 cm (2.6 – 7.1 in)

📐 Sizes are listed in centimeters with inch conversions for reference. Looking for a different size or color? Click "Custom Order" or send us a message. We’re happy to help! We can even create fully custom designs tailored to your scape.

This is a physical product, 3D-crafted with care using high-quality PETG - a strong, durable, and habitat-safe plastic material. Designed by Aquireef and crafted by Scapefin under exclusive release from January to July 2025. This item is scheduled to be retired from our store on July 22nd, 2025 and will no longer be available for purchase thereafter.