Rosslyn Chapel, formerly known as the Collegiate Chapel of St Matthew, is a 15th-century chapel located in the village of Roslin, Midlothian, Scotland.

Rosslyn Chapel was founded on a small hill above Roslin Glen as a Catholic collegiate church (with between four and six ordained canons and two boy choristers) in the mid-15th century. The chapel was founded by William Sinclair, 1st Earl of Caithness of the Scoto-Norman Sinclair family. Rosslyn Chapel is the third Sinclair place of worship at Roslin, the first being in Roslin Castle and the second (whose crumbling buttresses can still be seen today) in what is now Roslin Cemetery.

Since the late 1980s, the chapel has been the subject of speculative theories concerning a connection with the Knights Templar and the Holy Grail, and Freemasonry. It was prominently featured in this role in Dan Brown’s bestselling novel The Da Vinci Code (2003) and its 2006 film adaptation. Medieval historians say these accounts have no basis in fact. [Wikipedia]