By CHRIS PARSONS
Rooms with a view: Brave climbers who reach the summit of Barcelona Rock would be treated to glorious panoramic views across the Catalan city
Travellers staying in Barcelona come from across the world to see the Catalan city's stunning architecture, but many will never have seen a hotel as outlandish as this.
Polish architects who dreamt up the Barcelona Rock - a 100m hostel made especially for climbers - say guests can get their night's sleep perched perilously on a rock ledge overlooking the Spanish city.
Unique: The 100m-tall Barcelona Rock allows brave customers to sleep under the stars on the edge of rock ledges
It may be something of a health and safety nightmare and is certainly not what most would consider hotel comfort.
But thankfully those intrepid enough to sleep under the stars 100m from the ground are harnessed to the rock ledge to prevent them rolling off in their sleep.
The unusual concept hostel created by UGO was made for the Barcelona 2011 Bohemian Hostel for Backpackers international competition.
Competition rules asked designers to create a 100 metre tall tower hostel that includes relaxation areas, stores, cafe and at the same time created a new city landmark.
Polish firm UGO now hope the Barcelona Rock will become a 'unique place' in the Spanish city.
The proposed building will have fifty rooms, cinema, spa, cafe,pool, gym, bar, shops, and climbing walls for beginners.
Naturally, the architects planned the hostel so that those using the swimming pool can jump from the rock into the water.
The unique exterior would be made of rocks so advanced rock climbers can spend the night out using special equipment.
The elevation is made of stone blocks, each four meters high, mounted on stilts of reinforced concrete.
All mod cons: As well as various hotel luxuries inside, the proposed rock wall harnesses customers to the ledge to prevent them falling off in their sleep
These blocks are fixed some distance from each other to ensure air penetrates the building. The advantage of using stone in this climate is that it radiates heat at night and cools the air during the day.
UGO boss Hugon Kowalski said: 'Barcelona Rock hostel is supposed to be a unique place. It is supposed to become a new symbol of Barcelona.
'In search for inspiration we were trying to find something common for the city's architectural marks such as Sagrada Familia, Torre Agbar or the nearby Museum of Modern Art.
'We found it in Montserrat - in a mountain range near Barcelona, the highest elevation in Catalonia, you can see it from Barcelona.
'The stone from that mountain range was used for the buildings of the old city.' He said the idea was to make the building look like part of a mountain.
'The stone elevation would also be planted with greenery and provide shelter to birds.
Stunning: The Polish firm behind Barcelona Rock describe the plans for the their building as a 'unique place' in Barcelona
It's hoped the structure would become a natural feature of historic importance in the centre of the metropolis.
He added: 'There's a swimming pool, spa, gym, cinema, pub, shops and climbing walls for beginners.
'The outer elevation of the hotel forms climbing walls for more advanced climbers, who can spend the night there using special equipment.
'We hope the hostel will become a symbol of the city as Ayers Rock is for Australia.'