CoastDune Aquarium Décor Hide

A tall coastal ridge that introduces height, a sculpted rock wall, and a sheltered opening beneath the upper sandscape.

$13.49~~$14.99~~10% lower than Etsy

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Made to order · Ships in 1–5 business daysU.S. shipping $5.99 for the first item · +$1.99 each additional item · Shipping details

PETG plasticFor freshwater or saltwater aquariums

14 matte colorsChoose the finish that fits your aquascape

Simple careRinse with clean water before tank placement

Use the back wall as terrain

Build a coastal rise instead of a flat tank floor.

CoastDune creates a strong vertical transition with a rugged wall on one side and a raised shelf ready to carry sand, stones, moss, or plants. A tucked-away lower opening gives the structure a functional cave beneath the scenery.

Place it near a back or side wall in freshwater tanks, betta and shrimp setups, planted aquascapes, and displays that need height and a more dramatic substrate profile.

Raised sand shelf

Adds a second elevation for substrate, rocks, moss, and plants.

Hidden lower cave

Creates a sheltered opening beneath the visible landscape.

Tall rocky wall

Introduces height and a strong backdrop within the aquascape.

Size, placement, and comparison

Measure the vertical rise as carefully as the footprint.

CoastDune combines a broad base with one of the taller profiles in the aquarium collection. Check the selected size against the tank floor, water line, lid, plants, and nearby hardscape before committing to a back-wall or side-wall position.

Small5.82" × 5.90" × 4.88" (148 × 150 × 124mm)Exterior dimensions · L × W × H

Medium7.00" × 7.08" × 5.82" (178 × 180 × 148mm)Exterior dimensions · L × W × H

Large8.18" × 8.26" × 6.81" (208 × 210 × 173mm)Exterior dimensions · L × W × H

Placement plan

A back or side location can preserve foreground swimming space while showing the rocky wall and raised shelf. Keep the lower cave opening clear and leave a service gap so trapped debris can be reached without dismantling the whole layout.

Fit check

The outside dimensions help determine whether the terrain piece fits, but they do not guarantee animal clearance inside the lower shelter. Review every product angle and choose based on the individual inhabitant and usable tank space.

Compare another shapeDuneTide: A flowing dune-inspired ledge that creates a broad shaded shelter below the landscape. →Cliff Tower: A rugged moonrock cliff with a protected cave below and a planted ledge above. →

Plan the whole setup

Compare the fit before you choose.

Use these focused collections and practical guides to compare dimensions, placement, and the amount of shelter your aquarium needs.

Shop by styleNatural-looking cavesCompare products →Practical guidePlace an aquarium cave wellRead the guide →