Conghonas is a rather unusual WHS. I think it is true to say that there are no other (?) cultural WHS whose design and “manufacture” can be identified as the work a single named individual. The nearest which come to my mind are buildings by architects such as Horta and Rietveld Schroder and they clearly didn’t do the construction as well! (Similarly with Michelangelo’s role at the Vatican!) Recognition and preservation of the World’s “Fine Art” has not been dealt with by UNESCO under the Cultural Heritage banner which requires that such heritage be “sited” whereas much of such art is movable and therefore excluded. Yet, although the Basilica of Bom Jesus at Conghonas is technically inscribed as a complete building in its own right as well as for 2 associated works of art, it is for those works of art by one man, “Aleijadinho” that it is primarily recognised (In the case of the second work he did have the help of a few assistants/pupils as has often been traditional with large religious works),.
The 2 works are
a. The “12 Prophets” carved in stone and set on the terrace outside the Basilica which is situated on a hill on the outskirts of the town
b. The “Passion of Christ” – over 60 figures carved in wood and set as tableaux in 6 chapels near the Basilica
The story of Aleijadinho is the stuff of legend. The son of a black slave and unable to use his arms or legs after contracting leprosy in his youth he somehow learned how to sculpt with a hammer and chisel strapped to his arms. The “Prophets” were created at the start of the 19th century when he was already well into his 70s. They are no doubt recognised as artefacts of “outstanding universal value” not just for their intrinsic artistic value but as representatives of the development of Baroque art in Latin America.
Congonhas itself is a rather ugly and uninteresting town – do not confuse it with other wonderful “colonial” towns in Minas Gerais (2 of which are WHS and others of which could justifiably be!). As you only need a couple of hours for the site the essence of planning a visit to Conghonas is to arrange to get in and out on the same day e.g. on a trip to or from Ouro Preto. It is worth remembering also that the churches in a number of the more attractive nearby colonial towns such as Tiradentes and Mariana also contain work by Aleijadinho.
On that basis, it is in my view worth making the detour to Congonhas even if you are not a great aficionado of baroque art. The Brazilians regard him very highly and to see and appreciate his works is to take a step along the way of understanding the development of a separate Latin American and particularly Brazilian culture.