Overnight in the Deepest Hotel Room – Full Deep Sleep Review
The deepest hotel room on earth lies 1,375 feet below the ground in the abandoned Cwmorthin slate mine in Northern Wales in the United Kingdom. Centuries of history flow through the hundreds of chambers and two dozen floors. The creative people at Go Below transformed one of these chambers into one of the world’s most unique accommodations and you can spend the night here.
In April 2025, I slept in the Grotto at Deep Sleep, Go Below’s most unique room built directly into the rock. Getting here is no small feat – a healthy sense of adventure and good fitness level are required. Despite my fears of cave-ins or ghost encounters, I had an incredible time. This blog is a full Deep Sleep review covering everything you need to know if you too want to sleep far beneath the earth.
This post may contain affiliate links, which means I’ll receive a commission if you purchase through my link, at no extra cost to you.
What is Deep Sleep?
Deep Sleep is marketed as “is an experience like no other on Earth,” offering the opportunity to sleep deeper below the surface than anywhere else. Go Below, the operating company, has built a series of 4 wooden guest cabins and “the Grotto” room built in an old tunnel of the abandoned Cwmorthin/Oakeley mines in Wales. There are also 2 communal restrooms and a communal dining area.
Deep Sleep is more than just a hotel room – it’s the entire experience spanning 5PM on Day 1 to around 10AM on Day 2. It includes all your necessary equipment, the journey into/out of the mine, education about the history of this place, dinner, drinks (non-alcoholic), and breakfast.
This experience is for those who love a unique experience and are up for a challenge. The payoff is definitely worth the effort you put in!
Booking/Pricing
There are 2 types of accommodations you can book at Deep Sleep – the Grotto and the log cabins. Here’s a quick overview of each:
Log Cabins – £399
- 2 twin beds
- temperature-controlled, insulated
- wellie racks outside the door to keep water from dripping into your boots
Grotto – £599
- 1 double bed
- built directly into the rock to truly take in your surroundings
- more secluded, very quiet
- lots of heaters to make up for the lack of insulation
- has a sink with cold running water. Soap, lotion, and a towel are also provided.
- 2 USB and 2 USB-C outlets on each side of the bed (it’s possible the log cabins have these too but I didn’t get to see inside for myself)
Note that the price is per-cabin, so it’s the same if you go solo or share with someone else.
You can look online to see what dates are available for booking each room type. Since there’s only 1 Grotto room, this obviously books up quickly and you’ll need to secure your spot well in advance. For reference, we booked the Grotto five months in advance. Deep Sleep is also only available on Friday and Saturday nights. You cannot book online, but instead have to call Go Below to book. This phone call is to ensure you understand what you’re signing up for.
Know that this experience isn’t for everyone. In addition to a moderate fitness level, there’s a minimum age of 14 (accompanied by an adult). This experience may not be suitable for people with various health conditions, so speak to Go Below staff if you have any concerns before booking. Once you descend, there’s no backing out except for a true emergency and if that happens, everyone has to evacuate together. No one can be left behind.
Getting to Go Below
The meeting point for the adventure is Tanygrisiau Base, near Blaenau Ffestiniog in Wales. While it’s technically possible to get there by train, it’s difficult and time consuming depending on where in the UK you’re coming from.
Instead, I strongly recommend renting a car. Yes, they drive on the left in the UK, but having the freedom of a car provides you with a lot more freedom to stop along the way and ensure you get there on time. Rental cars are also quite inexpensive in the UK. We paid $34/day for our Hertz rental from Heathrow and the drive took us ~4.5 hours each way. There is free parking at the Tanygrisiau Base.
There are no restaurants or stores near the meeting point, so make sure you fuel up before you arrive. However, there is a port-a-potty on site. You have to arrive by 5PM, but I recommend arriving 15-30 minutes early as a buffer to give you time to sign the waiver, get gloves, use the restroom, etc.
The Deep Sleep Experience
Descending Into the Mine
From our meeting point, we had a steep ~30 minute walk up to the kit room, where we passed massive piles of slate. Our guide, Andy, explained that in the process of making roof tiles from slate, it’s difficult to get a perfect cut, and about 90% of the slate mined ends up as waste. Much of it is in these piles.
After getting our equipment on in the kit room, we headed to the mine entrance to start our descent. The Cwmorthin/Oakeley mine goes up 4 floors above lake level (numbered 1-4) and down 19 floors below (lettered A-S). The Deep Sleep chamber is on floor G, the lowest floor currently accessible, as all the floors below are underwater. This meant that we had to go not only deep into the mine, but also down 7 floors.
The mine felt like a labyrinth as we went down low corridors, passed 80 foot drop-offs, and walked through cavernous chambers. At one point, we had to rappel down 60 feet and the moment of stepping off the edge into the darkness is sure to get your heart racing. There was also a small zip line and a few sections where we had to clip into a rope along the wall to keep us safe from falling. The wellies we wore also proved very important as the water was calf-deep in some sections.
Along the way, Andy made sure to point out old mining equipment and passages and explain how they were used. Mining was a hard job. Miners worked 12 hour days, 6 days a week and largely worked by dim candlelight. Drilling a single hole could take a miner an entire day, which really makes the massive size of the mine so much more impressive.
The Deep Sleep Chamber
Entering the Deep Sleep chamber, you immediately see the dining area and just to the left, the 4 log cabins. Across from them are the restrooms and one of the employee cabins. You can also see the bridge that leads to the Grotto.
The chamber is the only place where we didn’t have to wear our safety gear, as it had been sealed off to ensure the safety of guests. Also, the chamber is locked from the inside overnight. While the mine is private, Go Below does lease out keys to other groups, so this just ensures no one can wander in overnight.
The 2 restrooms are communal. One is just a urinal for the men. The other has 2 toilets in it: 1 porcelain toilet for #1 and a special toilet for #2. For the latter, you have to line the toilet with a special bag, do your business, tie it up, and drop it down the chute. The restroom has running water, soap, and paper towels to wash your hands.
The chamber has WiFi, which worked pretty well in the communal area. The Grotto has it’s own router and network, which didn’t work as well as the main one. Regardless, pretty impressive to be connected with the outside world so far underneath the surface!
The Grotto Room
The Grotto room was everything we hoped it would be when we walked in. Built right into the rock, you can see the grain of the slate with one side being smooth and the other much more jagged. We laughed when we realized the wall at the back was just foam core with a picture of tiles printed on it! The caribeener coat hooks and sink were also a nice touch in the room.
I’m very glad we paid the extra money for the Grotto room. This room truly makes you feel like you’re sleeping in a mine deep beneath the earth.
The double bed was very cozy, with heaters under the bed and a heated blanket where each person can control their side. Ironically, I didn’t get a super “deep sleep,” but I will admit to user error(s):
- I should have turned off some of the heaters before I went to bed, because I woke up hot.
- At 3AM I found myself regretting my soda with dinner because I had to use the restroom.
- The lamp on my side of the bed had 3 settings and I didn’t know it turned it all the way off. I left a blue light illuminating the room, which kept it from being totally dark.
If you don’t make my mistakes, I’m sure you’ll sleep much better because it is so quiet and dark (in a good way, not a spooky way). My husband did find that the bed was too short for him at 6’1,” but he still slept very well.
The Food
When we arrived in the Deep Sleep chamber, another staff member, Jonty, was waiting for us and immediately offered us hot chocolate (regular or oat milk), coffee (regular or decaf) or tea. I had a hot chocolate which was delicious and the perfect way to stay warm.
Dinner was served around 8:30PM and we had our choice between Firepot dehydrated camping meals. There were options for various dietary restrictions, including gluten free, vegan, etc. I opted for the Smoky Tomato Paella and my husband got the Chile Con Carne and we both were happy with our selections. Jonty prepared each of our meals for us and as an added bonus, they were served in proper dishes, rather than having to eat out of the bag. To accompany our entrees, there was also warm bread rolls with butter, a salad, and cheese. There were also sodas (Sprite, Regular Coke, Diet Coke) and orange juice boxes available to drink.
After dinner, we were offered sticky toffee cake and custard for dessert, which included singing happy birthday to one of the other guests.
In the morning, breakfast was served at 8:30AM and was primarily a variety of pastries. There were also bananas, cheese, and a package oat bar snack.
I am gluten free and couldn’t eat everything offered, but there was still more than enough food for me and I was never hungry!
Getting Out of the Mine
Around 9AM, we put our gear back on and started our ascent back up to the mine entrance. Although it had taken us about 2.5 hours to descend, we reached the entrance in 45 minutes. The route back is much more straightforward and most of it takes place along the path used to haul mining carts up hundreds of feet. It’s very steep and a pretty solid workout. Thankfully we stopped on almost every floor to catch our breath because I was definitely winded!
What Gear is Provided?
The follow gear is provided by Go Below:
- Wellies (rain boots) – they have sizes 1-12 (UK sizing!) available. It’s helpful if you know your UK shoe size so you don’t have to try on too many pairs.
- Helmet with headlamp attached
- Climbing harness with via ferrata-style lanyard and a trolley for the zip line
- Gloves – the website said these would be £3 but our guide gave them to us all for free. They were definitely necessary to have!
What to Pack
You have to carry in anything you want to bring with you, so you should aim to pack light. My husband and I were able to bring everything we needed in 1 backpack between us. Keep in mind it’s about 50 degrees Fahrenheit (10C) in the mine year-round, so dress accordingly.
What to Wear
- Water-wicking long pants (we wore hiking pants and they were perfect)
- Long sleeve shirt
- Mid-layer jacket
- 1-2 pairs of socks (you may want an extra pair to make the wellies more comfortable)
- Sneakers for the walk to/from the mine
Packing List
- Backpack
- Extra layer (we each had 1 extra jacket we didn’t need)
- Medications you need
- Toiletries for an overnight stay
- Socks
- Underwear
- Change of clothes (we wore the same clothes both days because ours weren’t dirty)
- Portable charger & cords for your electronics
What other activities does Go Below offer?
Go Below offers 3 day-trip options in addition to Deep Sleep: Challenge, Hero Xtreme, and Ultimate Xtreme. Here’s a quick comparison chart of each from the Go Below website:
Deep Sleep isn’t the most hardcore trip that Go Below offers, but I think it’s the most unique. There are lots of places around the world where you can abseil, explore caves/mines, etc., but nowhere else can you sleep 1,375’ below the surface.
Final Thoughts
If you’ve seen Kara and Nate’s video showing their experience at Deep Sleep only 5 months before my trip, know that Go Below has made some updates since then. Although similar, the bathroom is different than the one shown in their video. The USB outlets by the bed in the Grotto also seem to be new.
This mine that once employed 20,000 men has been given some fresh new life with Go Below’s Deep Sleep and other day trip experiences. I’m so glad they’ve left all the artifacts as they were, allowing people like me to practically step back in time. The Grotto at Deep Sleep is definitely among the most unique places I’ve ever slept and was such a fun adventure. I hope this Deep Sleep review inspires you to book your own trip to this special place.
Be sure to pin this post for future planning!
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