Alberobello contains the largest concentration of trulli, dry-stone buildings characteristic of the Itria Valley in Puglia. Although corbelled stone construction has ancient Mediterranean precedents, the town’s surviving structures date mainly from the fourteenth century onward. Rural trulli served as shelters, stores, and dwellings, while those in Alberobello formed dense urban quarters. Their whitewashed rectangular walls and conical or pyramidal roofs create a distinctive skyline shaped by local limestone, limited timber, agricultural settlement, and skilled building traditions.

Builders excavated stone while cutting cisterns and clearing fields, then laid walls without mortar around a rubble core. Squinches carried the transition from rectangular rooms to a domed inner roof and an outer skin of overlapping limestone slabs called chianche or chiancarelle. Thick walls moderated temperature, small openings limited heat, and roof edges directed rainwater toward underground storage. Pinnacles and painted symbols could identify builders, owners, religious devotion, or protective beliefs, though modern explanations often assign firmer meanings than surviving evidence permits.

The settlement expanded under the counts of Conversano. By the mid-sixteenth century the Monti area contained dozens of trulli, and growth accelerated after 1620 with a mill, bakery, inn, and other services. A famous local tradition says mortarless roofs allowed landlords to dismantle houses quickly and evade royal taxes or restrictions. Fiscal control may have influenced construction, but the technique also reflected materials, custom, and practical adaptation. By the late eighteenth century several thousand people lived in the community.

In 1797 King Ferdinand IV ended feudal authority over the settlement and granted Alberobello the status of a royal town. Conventional masonry increasingly replaced new trulli, yet the older districts survived. Heritage protection began in the early twentieth century, with major designations between 1909 and 1936. Tourism later brought restoration and income but also converted many dwellings into shops and short-term accommodation. Some buildings remain residences, particularly in Aia Piccola, while Rione Monti has become more intensely commercial.

UNESCO inscribed the Trulli of Alberobello in 1996. The property includes the Monti and Aia Piccola districts and notable individual structures such as Trullo Sovrano and Casa d’Amore. Regular maintenance is essential because poorly repaired roofs admit water, while cement, altered openings, new services, and decorative commercialization can weaken authenticity. A trullo may contain replaced stones and renewed whitewash yet preserve its inherited form and technique. The site’s significance today lies in an enduring vernacular building system and the community that continues to adapt it.