The present invention discloses a method and an apparatus for removably attaching photogrammetric targets to a surface, in particular a method and an apparatus for removably attaching a magnetic target for a photogrammetry system to a surface of a structure. A retaining member may comprise a body, an engagement material associated with the body, and a magnetic material associated with the body. The engagement material may be configured for use in removably attaching the retaining member to the surface of the structure. The magnetic material may be configured for use in removably attaching a magnetic target to the retaining member.