The Guell Palace is a palace in Barcelona and is one of the works of architect Antoni Gaudí, which has been designated a UNESCO World Heritage Site. This nomination has officially recognized its universal value and its uniqueness as the masterpiece of human creativity. It was built as a town residence, for the rich industrialist Eusebi Güell, who was also one of the principal Catalan architect's clients. One of the major difficulties Gaudí faced was its lack of space, in the center of the city, near the Ramblas. Some rooms are therefore organized on several levels, such as the main salon to receive high society guests: the high-ceilinged rich ceiling has holes in which lanterns were placed at night, making it look like a starry sky. Among the features of the building are the catenary arches that Gaudí uses here for the first time and will be a constant element of his architectural language. The interior decorations are by the painter Aleix Clapés.