64P offers 6,287 to 48,403 SF of Class A lab, flex, tough tech, and office space in a fully redeveloped historic mill on the Charles River in Watertown Square. Core and shell work is complete, with flexible first- and second-floor availabilities, modernized building systems, exposed beams, higher ceilings, reinforced concrete floors, and amenity-rich common areas. Tenants benefit from direct Greenway access, fitness, showers, bike storage, conference amenities, and walkable access to restaurants, retail, transit, and housing. Class A lab, flex, tough tech, and office Core and shell complete Historic mill redevelopment New mechanical systems for life science users Higher ceilings and exposed beams Reinforced concrete floors Charles River frontage Direct Greenway bike path access Fitness wing, showers, bike storage, conference amenities Walkable Watertown Square location 5 minutes to Mass Pike and 20 minutes to Kendall Square