Circumstantial Adjunct

their extensive and well-preserved remains	stand	in spectacular natural surroundings
Carrier	Process	Attribute: circumstantial
Subject	Finite/Predicator	Adjunct

Note that a circumstantial Attribute is Adjunct, not Complement.  Compare:

it	has	a perpendicular nave, 12th-century Gothic choir, stunning stained glass windows and a Romanesque crypt
Carrier	Process	Attribute: possessed
Subject	Finite/Predicator	Complement