Website-exclusive pricing · New designs arrive here 7 days before Etsy

Aquarium caves · hides · décor

Build a better underwater world.

Sculptural shelters and aquascape pieces made to transform empty tank space into somewhere worth exploring.

Shop the collection Why shop direct?

10% lowerthan our Etsy prices

7 days earlyfor new model releases

14 colorsto fit your aquascape

HydraNest aquarium cave installed beneath pale sand

Early releaseHydraNest

Buried structure. Open viewing. A whole new layer to explore.

Made to orderModern aquascape designSmall-business careFreshwater-inspired forms

The complete collection

Find the right shape for every hidden space.

Nineteen caves, tunnels, bridges, and sculptural terrain pieces—each available in three sizes and fourteen colors.

BestsellerView product

Under-Gravel

DriftCore

$13.49~~$14.99~~

A buried, root-like tunnel system that turns the substrate line into a natural hideaway.

Size2.5" × 5.5" × 1.4" (65 × 140 × 36mm)Color

Early releaseView product

Under-Gravel

HydraNest

$13.49~~$14.99~~

An organic multi-chamber shelter with wide viewing angles and a dramatic cutaway profile.

Size4.72" × 3.03" × 1.96" (120 × 77 × 50mm)Color

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Caves & Hides

Moon Rock

$13.49~~$14.99~~

A cratered cave with rounded swim-through openings for a lunar-inspired aquascape.

Size2.87" × 4.72" × 2.44" (73 × 120 × 62mm)Color

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Caves & Hides

Stonebank

$16.19~~$17.99~~

A low-profile rock tunnel designed to blend into sand, gravel, and planted layouts.

Size4.72" × 4.68" × 2.51" (120 × 119 × 64mm)Color

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Aquascape Décor

Reef Niche

$16.19~~$17.99~~

A sculpted foreground niche that creates depth without overwhelming a compact tank.

Size6.29" × 4.80" × 4.09" (160 × 122 × 104mm)Color

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Aquascape Décor

Secret House

$17.99~~$19.99~~

A hidden underground room with architectural texture for a story-rich tank display.

Size6.88" × 3.34" × 4.37" (175 × 85 × 111mm)Color

NewView product

Caves & Hides

Nexora

$13.49~~$14.99~~

A reef-like cave system with hollow openings, flowing ridges, and an organic silhouette.

Size4.72" × 3.38" × 1.88" (120 × 86 × 48mm)Color

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Aquascape Décor

Cliff Tower

$16.19~~$17.99~~

A rugged moonrock cliff with a protected cave below and a planted ledge above.

Size4.72" × 3.81" × 3.97" (120 × 97 × 101mm)Color

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Under-Gravel

Sandflow

$11.69~~$12.99~~

A smooth, wave-shaped tunnel that creates a low-profile shelter beneath the substrate.

Size4.72" × 3.85" × 1.50" (120 × 98 × 40mm)Color

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Under-Gravel

TideMesa

$16.19~~$17.99~~

An elevated rock platform with rugged pillars and multiple shaded tunnels beneath.

Size5.90" × 5.59" × 2.87" (150 × 142 × 73mm)Color

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Under-Gravel

ShoreSand

$13.49~~$14.99~~

A winding underground cave with multiple entrances designed to vanish beneath sand or gravel.

Size6.88" × 3.54" × 2.63" (175 × 90 × 67mm)Color

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Under-Gravel

DuneTide

$13.49~~$14.99~~

A flowing dune-inspired ledge that creates a broad shaded shelter below the landscape.

Size6.29" × 5.15" × 3.26" (160 × 131 × 83mm)Color

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Caves & Hides

DuneCove

$16.19~~$17.99~~

A porous cove of flowing rock-like tunnels that blends into planted and sandy layouts.

Size6.57" × 6.14" × 2.40" (167 × 156 × 61mm)Color

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Aquascape Décor

CoastDune

$13.49~~$14.99~~

A tall coastal ridge with a raised sand shelf, rocky wall texture, and hidden cave opening.

Size5.82" × 5.90" × 4.88" (148 × 150 × 124mm)Color

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Caves & Hides

AquaVault

$13.49~~$14.99~~

A layered rocky terrain piece with hidden cave openings and a broad upper ledge.

Size4.30" × 4.75" × 1.75" (109 × 120 × 45mm)Color

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Aquascape Décor

Cave Tower

$17.99~~$19.99~~

A tall abstract sculpture formed by smooth, interconnected tunnels and open voids.

Size4.52" × 4.05" × 4.72" (115 × 103 × 120mm)Color

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Caves & Hides

RockBridge

$17.09~~$18.99~~

A rugged low-profile rock tunnel that doubles as a climbing or basking platform.

Size4.64" × 4.72" × 2.20" (118 × 120 × 56mm)Color

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Caves & Hides

Skull Cave

$17.09~~$18.99~~

A rocky skull-shaped cave that creates a dramatic shelter and gothic focal point.

Size4.09" × 4.72" × 3.14" (104 × 120 × 80mm)Color

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Caves & Hides

FluxDen

$13.49~~$14.99~~

A wavy sculptural cave with flowing planes, a sheltered core, and a landscape-ready profile.

Size4.72" × 4.60" × 2.48" (120 × 117 × 63mm)Color

Why TankHaven3D

Décor should do more than sit there.

Each piece begins with the behavior we want to encourage: swimming through, tucking away, claiming territory, or discovering a new path.

01
Designed around movement
Openings, tunnels, and profiles are selected to make the aquascape feel active.
02
Built for visual depth
Foreground niches and buried structures make use of space most décor ignores.
03
Prepared with care
Every piece is made to order and checked before it leaves our small shop.

DriftCore under-gravel aquarium shelter viewed from above

“A new addition to your underwater world.”

Choose your finish

From quiet neutrals to full-color personality.

Build a natural stone palette, match your plants, or make the cave the centerpiece. Choose from 14 available colors on every product.

Matte Ivory White

Sakura Pink

Lilac Purple

Matte Plum

Pistachio Green

Matte Ice Blue

Lemon Yellow

Orange

Desert Tan

Latte Brown

Dark Green

Navy Blue

Matte Ash Grey

Matte Black

Simple care

Ready your new piece for the tank.

Rinse thoroughly

Use clean water before placing your new décor into the aquarium.

Skip the soap

Do not use soap, detergent, or household cleaning chemicals.

Inspect regularly

Remove the piece if it becomes damaged or develops sharp edges.

Build a better underwater world.

Find the right shape for every hidden space.

Décor should do more than sit there.

From quiet neutrals to full-color personality.

Ready your new piece for the tank.

Rinse thoroughly

Skip the soap

Inspect regularly

Get new designs a week early.