620 S IL Route 31, also known as Liberty Square / Collective 31, is a multi-tenant office property located along the highly traveled IL Route 31 corridor in McHenry, Illinois, directly across from Northwestern Medicine McHenry Hospital. The approximately 10,058-square-foot building was originally constructed in the 1990s and recently underwent a comprehensive renovation in 2025, resulting in upgraded finishes, modernized common areas, and improvements to building systems. The property offers a variety of professional office configurations ranging from small individual suites to larger multi-office layouts, making it suitable for medical, wellness, and traditional office users. Available suites feature private restrooms, multiple office layouts, and select spaces with plumbing infrastructure to accommodate specialized professional uses. The property benefits from strong visibility, ample on-site parking, convenient access to surrounding commercial amenities, and proximity to major transportation corridors serving McHenry County.