Between the floors of the LMB’s building are full height Interstitial Service Voids (ISVs), which house the ductwork, pipes and services. These ISVs are normally only accessible for maintenance and modifications by the Estates and Facilities team. The team recently ran some “Secret LMB Tours” for the LMB’s students to allow them to see behind the scenes in these areas and this photo for day 158 of #LMB365 was taken while they found out more about how the building functions.