Trinidad's Historical Centre, declared a UNESCO World Heritage site in 1988, boats a wealth of architectural buildings dating from the 18th and 19th centuries around Plaza Mayor (main square) when trade in sugar from the nearby Valle de los Ingenios and slaves, brought great riches to the area. Many of the buildings surrounding the central square belonged to the wealthy landowners of the city.

When the trade in sugar diminished and the slave trade ended in the mid-19th century, Trinidad became a backwater and because little building work was carried until the 1950s many of the historic buildings and streets were preserved, especially the grand constructions in the immediate vicinity of the Plaza Mayor. Today, most of the houses surrounding the square are home to museums.

The colonial houses of Trinidad are typified by red terracotta tiled roofs supported out beyond the walls by wooden beams. Pastel-coloured paintwork for the houses is normal with wood and plasterwork details picked out in different colours to the brickwork. The large main door typically has a smaller entrance door (or doors) cut into it. In contrast to the houses of the same period in Havana the door tends to open directly onto a living area, rather than having a vestibule or entrance hall. The doors are often surrounded by architectural plaster mouldings. It is one of the most photographed landscapes in Cuba, as well as a must-see place in every tour made in that village. The monumental value of the 65 sites that form the valley increases the interest to visit this place, where important vestiges of the island's sugar colonization still survive.

During the 18th and late 19th century, the rising national middle class who had earned their money from sugar production settled in this vast and fertile valley that soon became one of the largest sugar producing regions in the country. Hundreds of slaves died while working on the magnificent sugar mills and the opulent constructions that were built in the middle of the exuberant natural environment.

The regal mansion of the slave-owner Mariano Borrel still astonishes because of its colossal columns, its arcades, its roof, and the elegance of its well-preserved interiors holding frescos with exotic landscapes and friezes set out by the Italian artist Daniel Dall Aglio, the same artist who decorated the Cantero Palace in the city of Trinidad.

The tower stands 143 feet (43.5 meters) high a mile away from the house building of the sugar refinery Buena Vista, a house that defies time. Less ostentatious than the ones owned by the rich magnates, this house building is, however, a great example of the construction that the middle class used; everlasting and beautiful materials that can be seen today in the eleven house buildings that are still preserved.

Along with the archaeological remains from the historical sugar refineries, the natural beauty of the valleys La Pastora, Santa Rosa, San Luis, and the plains of Agabama Valley can conquer anyone. The rivers that run through these valleys form ideal places for recreation and add considerably to the aesthetics of the landscape.

For all these reasons, the Sugar Mill Valley, together with the Historical Centre of Trinidad, was declared by UNESCO Cultural Patrimony of Humanity in 1988. In parallel, the World Monument Fund, that searches and promotes financing for endangered patrimonial and historical places, has joined the incentives for recovering or reconstructing the remains which perpetuate life in the Sugar Mill Valley.