• The Hollow Arch - Hollow
  • The Hollow Arch - Hollow
  • Triple Entrance Aquarium and Terrarium Corner Cave - Leopard Gecko Hide - Hollow
1 4

The Hollow Arch

The Hollow Arch

Color: Black
€36,90
€36,90
Sale Sold out

Handmade to order

30-Day Money-back

Aquarium safe PLA

Free shipping

1-4 Days production

5-8 Days to EU/USA

We stand behind this cave

Tested for 6+ months in real setups & backed by a 2-year warranty.
Product description & dimensions

The Hollow Arch Aquarium Cave Specifications:

Material: Aquarium cave made with aquarium safe PLA, it does not affect water parameters

Dimensions:

250 x 130 x 75 mm / 9.84 × 5.12 × 2.95 in
Opening: 100 x 70 mm / 3.94 × 2.76 in

Tank size in the pictures: 45x17x17 cm

View full details

Easy to set up and style

Just place it against the glass, add substrate around it, and place plants over and inside it. That’s it. In just a few simple steps, it creates a mesmerizing underground world that adds depth, shelter, and a natural look to your setup.

Easy to clean

This cave features a large entrance that makes it easy to remove debris or waste. As aquascapers, we design every cave with easy maintenance in mind, so it stays practical in real long term planted tank use.

Functional shelter

It creates natural hiding spots, offers protection from light, helps reduce stress for fish and shrimp. Aquarium-Safe Material: Crafted from biodegradable, biosourced, and recyclable PLA, it does not affect water chemistry.
  • 5 stars: 17 (85%)
  • 4 stars: 2 (10%)
  • 3 stars: 0 (0%)
  • 2 stars: 0 (0%)
  • 1 star: 1 (5%)
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geeklord7

These are amazing, over the top quality! Definetly worth the wait for them to print and eventually be shipped. The seller was very understanding when there was over a week of silence, and assured me that my order was still on process since it was print to order (and I had gambled with him and made a pretty large order). But once shipped, it arrived quickly to me in the US. Again, the quality is so good, it makes me wish I had ordered a custom piece for my paludarium. I plan on ordering from this store in the future. Hopefully I can add pictures once the paludarium build is complete.

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Zach w.

This item was good for my shrimp

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Sign i.w.A.u.

The caves are very well made

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Amanda

He did a great job and when he accidentally sent me the wrong one he got the new one sent out super fast. Thanks!!

A
Amanda

Can't wait to put this in my tank!

C
CJ

Looks great. Not The edges aren’t too sharp.

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gregory

Item doesn’t fit flush. Substrate falls through. Still waiting on seller to get back to me on delivery issue.

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Art

I tried to secure several different ways in my tank, but it kept filling with sand nothing on it is square. Nothing fit against the tank flush so Sam just kept coming in. I tried silicone. I tried underwater adhesive. It was a waste of money for me. I sent the owner. A message is their instructions. I never heard back. I took it out of my tank now I’m trying to get my water back to normal. I think I threw it away. I was still disgusted and mad and this thing was not cheap either.

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danielled365

I didn't read the dimensions and that's on me but ykw theyre perfect. I can't wait to set the tank up.

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Jeanette

They're really nice and just what I wanted. The sparkly marble is great
Shipping was great.

A
Alex

Such a cool and unique piece!

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Grace M.

I should have waited to review until my tank was all set up but I just can't wait. I will 1000% order again. The color is absolutely perfect and matches my river rock substrate perfectly and I believe it will blend in beautifully. The only challenge will be deciding which one to get next because the possibilities seems endless with how you could arrange these! It's often hard for me to find hides large enough for my freshwater crayfish but I am thrilled to have found this shop! Thank you so much for making it easy to order, great communication, good prices, packaged with care- I will be back for more!

M
Marius

Lieferung war top, Kommunikation mit dem Verkäufer ebenfalls.
Gibt nichts auszusetzen.

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Jennifer

Great Seller! Great product! I can’t wait to install into my terrarium

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Magnus

Love it! Bought a different one before and put one in each front corner of my aquarium. Its really sturdy and over all really nice material and texture. Rough makes it blend in in a nice way.

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stephane

envoie rapide service client super

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Andrea

Alles o.K. mit dem Produkt.

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Ally

My only regret was not getting the bigger size!!

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T

Very pleased, they look great in the aquarium. Thanks

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Jay

Great product, fit in the corner nicely
Why settle for less?

Let's compare

We’re so confident you’ll love your cave that every order comes with a 30-day money-back guarantee and a 2-year warranty. Caves are what we do. And we make them better than anyone.
Hollow Generic caves Mass produced
Easy to clean & maintain
Tested in planted tanks
Aquarium-safe materials
Blends naturally into the tank
Designed by an aquascaper
GOT QUESTIONS?

Frequently Asked Questions

About the caves

No. Every piece is made from aquarium-safe PLA that is biodegradable, biosourced, and fully inert. It will not affect your pH, hardness, or any other water parameter. Safe for fish, shrimp and marine aquariums.
Yes. Our pieces are suitable for terrariums and reptile setups as well as aquariums. Check the individual product page for compatibility details, especially dimensions, if your animal fits through the entrance comfortably, you are good to go! The rest is design preference. Disclaimer: Do not put it directly near high heat (45°C+/113°F+)
The large openings are intentional, so most caves are easy to clean with a standard aquascaping tool kit. A magnetic cleaner and a soft brush or toothbrush are highly recommended for the surrounding glass. We use the Chihiros Mini on all of our cave tanks. A regular hose is used to clean debris inside the cave.
The first step is to check the dimensions on the individual product page, below "Add to cart". If your animal can comfortably fit through the entrance, you are good to go. Beyond that, the choice is mostly visual: most caves can work in most tanks. A smaller cave works well as a subtle detail or accent piece, while a larger one creates a stronger focal point in the scape. Do not overthink it, our caves are designed to blend naturally into the setup, regardless of the style of your tank. That is exactly what they are made to do.

Shipping and ordering

Processing times: 1 - 4 days (every item is made to order and hand finished). Delivery times by destination: EU, UK and USA: 5 - 8 days. Canada: 7 - 10 days. Asia: 12 - 30 days. Australia and New Zealand: 12 - 20 days.
They are designed and made in house. Built to be sturdy and durable, they are made to hold up well during normal use and transit. Packed with care and shipped globally with tracking.
We offer a 30-day money back guarantee. If you are not happy with your order for any reason, contact us and we will sort it out. No complicated process, no awkward questions.
Absolutely. Use the live chat, WhatsApp (+356 9997 2230) or the contact page and we will get back to you quickly. We are happy to help you choose the right size or colour for your specific tank and animal.
Orders placed in the USA are shipped from our partner based in Kansas. Orders placed anywhere else in the world are shipped from Malta, Europe. Products are exactly the same in both places.

About Hollow

Hollow is a small independent business run by an aquascaper. Every design is created and tested in real planted tank conditions before it goes on sale. This is not mass-produced or dropshipping.
We started on Etsy and built our reputation there — that is where our 2,000 reviews come from. This website gives us more flexibility and lets us serve customers directly. You get the same quality on Etsy and on our website, however delivery is quicker if you order here.
Yes! Contact us on WhatsApp +356 9997 2230, tell us what animal and tank size you have. We will get back to you with a recommendation and price.
👍 just as described and fast
Jana