Cryogenic Observatory for SIgnatures seen in Next-generation Underground Searches (COSINUS)
will use cryogenic sodium iodide (NaI) calorimeters to search for dark matter. Recently, the
construction of an underground facility at Laboratori Nazionali del Gran Sasso (LNGS) for
COSINUS has been completed. The features of the COSINUS facility allow for a low background
environment for rare event searches. This facility will house a dry dilution refrigerator, which
will sit in a drywell inside a water tank. The water tank will be instrumented with photomultiplier
tubes and serve as an active muon veto as well as a passive shield