The Irish Seismological Lithospheric Experiment (ISLE) was originally designed to investigate the deep lithospheric and asthenospheric structure across the late-Caledonian Iapetus Suture Zone in southern Ireland. The project was a collaboration between the Dublin Institute for Advanced Studies (DIAS), Ireland, and the Geophysical Institute (GPI) of the University of Karlsruhe, Germany. It was the first passive teleseismic experiment conducted in Ireland, building upon a large body of earlier work on the crustal structure offshore and onshore Ireland, based on controlled source seismics and potential field studies. The Irish Seismological Upper Mantle Experiment (ISUME) was a continuation of ISLE by DIAS to extend the data coverage to most of Ireland. Data are available at the GEOFON data centre under network code 1M.