The sixth-century church of Santa Maria Antiqua in the Roman Forum, buried below a landslide in 847, will be open to the public in conjunction with the exhibit "Santa Maria Antiqua. Tra Roma e Bisanzio" from March 17-September 11, 2016. Entrance is from the Roman Forum, with a combined ticket to the Forum, Palatine and Coliseum. A multimedia history of the church and its excavation and restoration since 1900 is here. Ticket purchase information is on the Coopculture website (link).
Photographs of Santa Maria Antiqua (architecture, paintings, inscriptions) are at this link.