(hotel Mysterius) This historical residential building in Prague 1 was converted into an apartment hotel. Installing a complete range of modern technologies in the confined space of a historical building turned out highly challenging. We have installed air-conditioning, a cooling system and all cabling and piping. The project included renovation of the façade and a terazzo staircase, luxurious finishing, preservation of historical elements, furnishing of the guest rooms and construction of a restaurant and technical facilities in underground premises.