The Series Historic Buildings in Transylvania, launched in 1993, presents the most precious examples of Transylvanian built heritage connected to the Hungarian culture, with the purpose of drawing the general public's attention on values, heritage and our responsibilities towards these. The publications of this series are recommended especially to those who at present own or use such values, but also to those who are interested in history, architecture and the Transylvanian art.

Number 11 of the Series Historic Buildings in Transylvania presents the oldest historic building in Odorheiu Secuiesc, the Sacred Heart Chapel. Its quatrefoil central layout, a rare architectural solution in Transylvania, follows a western European model. A presumably 18^th century wall protects the chapel built from boulders and covered with shingles. Its original vault, damaged during a Tatar attack in 1661, was replaced in 1662 with a coffered ceiling with floral decoration. The specialists dated the chapel to the 13^th century; however a coin from 1561, found under the building's wall during an archaeological excavation conducted in 1974, questioned the chapel's mediaeval origin.