It is the most important sanctuary in Vilnius. It is a unique masterpiece of global architecture. Laurynas Gucevičius who prepared the design of reconstruction of the cathedral wanted to emphasise the values of the Enlightenment Epoch – mind and temperance. Such was Saint Casimir, the patron of Lithuania, to whom the most ornate chapel has been dedicated in the Archcathedral, today considered to be one of the most valuable Baroque monuments in Vilnius. The vault of the cathedral in which meritorious people were laid to rest is a must-see object. As many as 27 crypts of different depth and size have been discovered under the floor of the cathedral.