The sights in Alberobello that have made this city well known around the world and have actually allowed it to earn a place on the UNESCO World Heritage list are the “trulli”, traditional buildings made of limestone slabs without the use of cement or mortar. Initially, these were buildings constructed for the poor and, theoretically, the absence of cement or mortar made them easy to disassemble in order to avoid property taxes. Given the efficient design, though, many citizens of Alberobello decided to expand upon the trullo design.
One of these expansions resulted in the creation of the “Trullo Sovrano”, or “Sovereign Trullo”, so called because of its large proportions. Constructed in the first half of the 18th century, it is the only trullo that is composed of two floors. Many consider it the highest technical achievement in the area of trullo construction. The anonymous builder constructed the ceiling of the first floor in the form of a vault with crossbeams, supported by four Romanesque arches that each leaned on the main walls; the staircase that leads to the second floor is carved into the thick wall of the building. Each inch of space is efficiently used, with the creation of niches and alcoves within the walls themselves.